The movement of cells or organisms toward or away from a substance in response to its concentration gradient.
The movement of leukocytes in response to a chemical concentration gradient or to products formed in an immunologic reaction.
Chemical substances that attract or repel cells. The concept denotes especially those factors released as a result of tissue injury, microbial invasion, or immunologic activity, that attract LEUKOCYTES; MACROPHAGES; or other cells to the site of infection or insult.
Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.
A genus of protozoa, formerly also considered a fungus. Its natural habitat is decaying forest leaves, where it feeds on bacteria. D. discoideum is the best-known species and is widely used in biomedical research.
A formylated tripeptide originally isolated from bacterial filtrates that is positively chemotactic to polymorphonuclear leucocytes, and causes them to release lysosomal enzymes and become metabolically activated.
The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
A CXC chemokine that is chemotactic for T-LYMPHOCYTES and MONOCYTES. It has specificity for CXCR4 RECEPTORS. Two isoforms of CXCL12 are produced by alternative mRNA splicing.
Proteins found in any species of bacterium.
Group of chemokines with paired cysteines separated by a different amino acid. CXC chemokines are chemoattractants for neutrophils but not monocytes.
A family of G-protein-coupled receptors that was originally identified by its ability to bind N-formyl peptides such as N-FORMYLMETHIONINE LEUCYL-PHENYLALANINE. Since N-formyl peptides are found in MITOCHONDRIA and BACTERIA, this class of receptors is believed to play a role in mediating cellular responses to cellular damage and bacterial invasion. However, non-formylated peptide ligands have also been found for this receptor class.
The minor fragment formed when C5 convertase cleaves C5 into C5a and COMPLEMENT C5B. C5a is a 74-amino-acid glycopeptide with a carboxy-terminal ARGININE that is crucial for its spasmogenic activity. Of all the complement-derived anaphylatoxins, C5a is the most potent in mediating immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE), smooth MUSCLE CONTRACTION; HISTAMINE RELEASE; and migration of LEUKOCYTES to site of INFLAMMATION.
Cell surface glycoproteins that bind to chemokines and thus mediate the migration of pro-inflammatory molecules. The receptors are members of the seven-transmembrane G protein-coupled receptor family. Like the CHEMOKINES themselves, the receptors can be divided into at least three structural branches: CR, CCR, and CXCR, according to variations in a shared cysteine motif.
High-affinity G-protein-coupled receptors for INTERLEUKIN-8 present on NEUTROPHILS; MONOCYTES; and T-LYMPHOCYTES. These receptors also bind several other CXC CHEMOKINES.
A whiplike motility appendage present on the surface cells. Prokaryote flagella are composed of a protein called FLAGELLIN. Bacteria can have a single flagellum, a tuft at one pole, or multiple flagella covering the entire surface. In eukaryotes, flagella are threadlike protoplasmic extensions used to propel flagellates and sperm. Flagella have the same basic structure as CILIA but are longer in proportion to the cell bearing them and present in much smaller numbers. (From King & Stansfield, A Dictionary of Genetics, 4th ed)
Phenomenon of cell-mediated immunity measured by in vitro inhibition of the migration or phagocytosis of antigen-stimulated LEUKOCYTES or MACROPHAGES. Specific CELL MIGRATION ASSAYS have been developed to estimate levels of migration inhibitory factors, immune reactivity against tumor-associated antigens, and immunosuppressive effects of infectious microorganisms.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
High-affinity G-protein-coupled receptors for INTERLEUKIN-8 present on NEUTROPHILS; MONOCYTES; and BASOPHILS.
Physiological processes and properties of BACTERIA.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
Large, phagocytic mononuclear leukocytes produced in the vertebrate BONE MARROW and released into the BLOOD; contain a large, oval or somewhat indented nucleus surrounded by voluminous cytoplasm and numerous organelles.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
A member of the CXC chemokine family that plays a role in the regulation of the acute inflammatory response. It is secreted by variety of cell types and induces CHEMOTAXIS of NEUTROPHILS and other inflammatory cells.
CXCR receptors with specificity for CXCL12 CHEMOKINE. The receptors may play a role in HEMATOPOIESIS regulation and can also function as coreceptors for the HUMAN IMMUNODEFICIENCY VIRUS.
Cells specialized to detect chemical substances and relay that information centrally in the nervous system. Chemoreceptor cells may monitor external stimuli, as in TASTE and OLFACTION, or internal stimuli, such as the concentrations of OXYGEN and CARBON DIOXIDE in the blood.
A dynamic actin-rich extension of the surface of an animal cell used for locomotion or prehension of food.
Cell surface proteins that bind amino acids and trigger changes which influence the behavior of cells. Glutamate receptors are the most common receptors for fast excitatory synaptic transmission in the vertebrate central nervous system, and GAMMA-AMINOBUTYRIC ACID and glycine receptors are the most common receptors for fast inhibition.
Group of chemokines with adjacent cysteines that are chemoattractants for lymphocytes, monocytes, eosinophils, basophils but not neutrophils.
The major metabolite in neutrophil polymorphonuclear leukocytes. It stimulates polymorphonuclear cell function (degranulation, formation of oxygen-centered free radicals, arachidonic acid release, and metabolism). (From Dictionary of Prostaglandins and Related Compounds, 1990)
Class of pro-inflammatory cytokines that have the ability to attract and activate leukocytes. They can be divided into at least three structural branches: C; (CHEMOKINES, C); CC; (CHEMOKINES, CC); and CXC; (CHEMOKINES, CXC); according to variations in a shared cysteine motif.
Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.
A chemokine that is a chemoattractant for MONOCYTES and may also cause cellular activation of specific functions related to host defense. It is produced by LEUKOCYTES of both monocyte and lymphocyte lineage and by FIBROBLASTS during tissue injury. It has specificity for CCR2 RECEPTORS.
Adherence of cells to surfaces or to other cells.
Orientation of intracellular structures especially with respect to the apical and basolateral domains of the plasma membrane. Polarized cells must direct proteins from the Golgi apparatus to the appropriate domain since tight junctions prevent proteins from diffusing between the two domains.
Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)
Effective in the initiation of protein synthesis. The initiating methionine residue enters the ribosome as N-formylmethionyl tRNA. This process occurs in Escherichia coli and other bacteria as well as in the mitochondria of eucaryotic cells.
CCR receptors with specificity for CHEMOKINE CCL2 and several other CCL2-related chemokines. They are expressed at high levels in T-LYMPHOCYTES; B-LYMPHOCYTES; MACROPHAGES; BASOPHILS; and NK CELLS.
A CC-type chemokine with specificity for CCR7 RECEPTORS. It has activity towards T LYMPHOCYTES and B LYMPHOCYTES.
Phosphotransferases that catalyzes the conversion of 1-phosphatidylinositol to 1-phosphatidylinositol 3-phosphate. Many members of this enzyme class are involved in RECEPTOR MEDIATED SIGNAL TRANSDUCTION and regulation of vesicular transport with the cell. Phosphatidylinositol 3-Kinases have been classified both according to their substrate specificity and their mode of action within the cell.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
CCR receptors with specificity for a broad variety of CC CHEMOKINES. They are expressed at high levels in MONOCYTES; tissue MACROPHAGES; NEUTROPHILS; and EOSINOPHILS.
Assays that measure the rate of migration of LEUKOCYTES. They may involve a variety of techniques such as measuring the movement of leukocytes through substrates such as AGAROSE gels or the rate of exit of cells from a glass capillary.
A sub-family of RHO GTP-BINDING PROTEINS that is involved in regulating the organization of cytoskeletal filaments. This enzyme was formerly listed as EC 3.6.1.47.
A CC-type chemokine that is a chemoattractant for EOSINOPHILS; MONOCYTES; and LYMPHOCYTES. It is a potent and selective eosinophil chemotaxin that is stored in and released from PLATELETS and activated T-LYMPHOCYTES. Chemokine CCL5 is specific for CCR1 RECEPTORS; CCR3 RECEPTORS; and CCR5 RECEPTORS. The acronym RANTES refers to Regulated on Activation, Normal T Expressed and Secreted.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.
The process in which the neutrophil is stimulated by diverse substances, resulting in degranulation and/or generation of reactive oxygen products, and culminating in the destruction of invading pathogens. The stimulatory substances, including opsonized particles, immune complexes, and chemotactic factors, bind to specific cell-surface receptors on the neutrophil.
C5 plays a central role in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C5 is cleaved by C5 CONVERTASE into COMPLEMENT C5A and COMPLEMENT C5B. The smaller fragment C5a is an ANAPHYLATOXIN and mediator of inflammatory process. The major fragment C5b binds to the membrane initiating the spontaneous assembly of the late complement components, C5-C9, into the MEMBRANE ATTACK COMPLEX.
The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).
Granular leukocytes with a nucleus that usually has two lobes connected by a slender thread of chromatin, and cytoplasm containing coarse, round granules that are uniform in size and stainable by eosin.
CXCR receptors that are expressed on the surface of a number of cell types, including T-LYMPHOCYTES; NK CELLS; DENDRITIC CELLS; and a subset of B-LYMPHOCYTES. The receptors are activated by CHEMOKINE CXCL9; CHEMOKINE CXCL10; and CHEMOKINE CXCL11.
Established cell cultures that have the potential to propagate indefinitely.
Cell surface proteins that bind LIPOXINS with high affinity and trigger intracellular changes influencing the behavior of cells.
A promyelocytic cell line derived from a patient with ACUTE PROMYELOCYTIC LEUKEMIA. HL-60 cells lack specific markers for LYMPHOID CELLS but express surface receptors for FC FRAGMENTS and COMPLEMENT SYSTEM PROTEINS. They also exhibit phagocytic activity and responsiveness to chemotactic stimuli. (From Hay et al., American Type Culture Collection, 7th ed, pp127-8)
A monocyte chemoattractant protein that has activity towards a broad variety of immune cell types. Chemokine CCL7 has specificity for CCR1 RECEPTORS; CCR2 RECEPTORS; and CCR5 RECEPTORS.
A species of motile, free-living, gram-negative bacteria that occur in the soil. They are aerobic or microaerophilic and are sometimes capable of nitrogen fixation.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
A genus of flexible, spiral rods found in hydrogen sulfide-containing mud, sewage, and polluted water. None of the species properly referred to in this genus are pathogenic.
Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.
A CC-type chemokine with specificity for CCR7 RECEPTORS. It has activity towards DENDRITIC CELLS and T-LYMPHOCYTES.
The relationship between the dose of an administered drug and the response of the organism to the drug.
Heparin-binding proteins that exhibit a number of inflammatory and immunoregulatory activities. Originally identified as secretory products of MACROPHAGES, these chemokines are produced by a variety of cell types including NEUTROPHILS; FIBROBLASTS; and EPITHELIAL CELLS. They likely play a significant role in respiratory tract defenses.
One of the virulence factors produced by BORDETELLA PERTUSSIS. It is a multimeric protein composed of five subunits S1 - S5. S1 contains mono ADPribose transferase activity.
A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.
CCR receptors with specificity for CHEMOKINE CCL11 and a variety of other CC CHEMOKINES. They are expressed at high levels in T-LYMPHOCYTES; EOSINOPHILS; BASOPHILS; and MAST CELLS.
CCR receptors with specificity for CHEMOKINE CCL19 and CHEMOKINE CCL21. They are expressed at high levels in T-LYMPHOCYTES; B-LYMPHOCYTES; and DENDRITIC CELLS.
Methods utilizing the principles of MICROFLUIDICS for sample handling, reagent mixing, and separation and detection of specific components in fluids.
White blood cells. These include granular leukocytes (BASOPHILS; EOSINOPHILS; and NEUTROPHILS) as well as non-granular leukocytes (LYMPHOCYTES and MONOCYTES).
The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)
Chemokines that are chemoattractants for monocytes. These CC chemokines (cysteines adjacent) number at least three including CHEMOKINE CCL2.
Phosphatidylinositols in which one or more alcohol group of the inositol has been substituted with a phosphate group.
Microscopy in which television cameras are used to brighten magnified images that are otherwise too dark to be seen with the naked eye. It is used frequently in TELEPATHOLOGY.
Mitogenic peptide growth hormone carried in the alpha-granules of platelets. It is released when platelets adhere to traumatized tissues. Connective tissue cells near the traumatized region respond by initiating the process of replication.
A class of cell surface leukotriene receptors with a preference for leukotriene B4. Leukotriene B4 receptor activation influences chemotaxis, chemokinesis, adherence, enzyme release, oxidative bursts, and degranulation in polymorphonuclear leukocytes. There are at least two subtypes of these receptors. Some actions are mediated through the inositol phosphate and diacylglycerol second messenger systems.
The largest family of cell surface receptors involved in SIGNAL TRANSDUCTION. They share a common structure and signal through HETEROTRIMERIC G-PROTEINS.
A CXC chemokine with specificity for CXCR2 RECEPTORS. It has growth factor activities and is implicated as a oncogenic factor in several tumor types.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
Proteins obtained from ESCHERICHIA COLI.
A CC chemokine with specificity for CCR5 RECEPTORS. It is a chemoattractant for NK CELLS; MONOCYTES and a variety of other immune cells. This chemokine is encoded by multiple genes.
A G-protein-coupled receptor that signals an increase in intracellular calcium in response to the potent ANAPHYLATOXIN peptide COMPLEMENT C5A.
Proteins prepared by recombinant DNA technology.
A CX3C chemokine that is a transmembrane protein found on the surface of cells. The soluble form of chemokine CX3CL1 can be released from cell surface by proteolysis and act as a chemoattractant that may be involved in the extravasation of leukocytes into inflamed tissues. The membrane form of the protein may also play a role in cell adhesion.
The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.
A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)
The study of fluid channels and chambers of tiny dimensions of tens to hundreds of micrometers and volumes of nanoliters or picoliters. This is of interest in biological MICROCIRCULATION and used in MICROCHEMISTRY and INVESTIGATIVE TECHNIQUES.
A phosphatidylinositol 3-kinase subclass that includes enzymes formed through the association of a p110gamma catalytic subunit and one of the three regulatory subunits of 84, 87, and 101 kDa in size. This subclass of enzymes is a downstream target of G PROTEIN-COUPLED RECEPTORS.
The rate dynamics in chemical or physical systems.
Derivatives of PHOSPHATIDIC ACIDS that lack one of its fatty acyl chains due to its hydrolytic removal.
A subclass of enzymes of the transferase class that catalyze the transfer of a methyl group from one compound to another. (Dorland, 28th ed) EC 2.1.1.
A CC-type chemokine that is specific for CCR3 RECEPTORS. It is a potent chemoattractant for EOSINOPHILS.
Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.

Cell polarization: chemotaxis gets CRACKing. (1/5128)

An early stage in the establishment of cell polarity during chemotaxis of Dictyostelium dicoideum has been identified by a recent study; the new results also show that the development of cell polarity does not rely upon cytoskeletal rearrangement, and may use a spatial sensing mechanism.  (+info)

Tyrosine phosphorylation is required for actin-based motility of vaccinia but not Listeria or Shigella. (2/5128)

Studies of the actin-based motility of pathogens have provided important insights into the events occurring at the leading edge of motile cells [1] [2] [3]. To date, several actin-cytoskeleton-associated proteins have been implicated in the motility of Listeria or Shigella: vasodilator-stimulated phosphoprotein (VASP), vinculin and the actin-related protein complex of Arp2 and Arp3 [4] [5] [6] [7]. To further investigate the underlying mechanism of actin-tail assembly, we examined the localization of components of the actin cytoskeleton including Arp3, VASP, vinculin and zyxin during vaccinia, Listeria and Shigella infections. The most striking difference between the systems was that a phosphotyrosine signal was observed only at the site of vaccinia actin-tail assembly. Micro-injection experiments demonstrated that a phosphotyrosine protein plays an important role in vaccinia actin-tail formation. In addition, we observed a phosphotyrosine signal on clathrin-coated vesicles that have associated actin-tail-like structures and on endogenous vesicles in Xenopus egg extracts which are able to nucleate actin tails [8] [9]. Our observations indicate that a host phosphotyrosine protein is required for the nucleation of actin filaments by vaccinia and suggest that this phosphoprotein might be associated with cellular membranes that can nucleate actin.  (+info)

Role of thrombin receptor in breast cancer invasiveness. (3/5128)

Invasion, the ability of an epithelial cancer cell to detach from and move through a basement membrane, is a central process in tumour metastasis. Two components of invasion are proteolysis of extracellular matrix and cellular movement through it. A potential promoter of these two processes is thrombin, the serine proteinase derived from the ubiquitous plasma protein prothrombin. Thrombin promotes the invasion of MDA-MB231 breast tumour cells (a highly aggressive cell line) in an in vitro assay. Invasion by MDA-MB436 and MCF-7 cells, less aggressive cell lines, is not promoted by thrombin. Thrombin, added to the cells, is a stimulator of cellular movement; fibroblast-conditioned medium is the chemotaxin. Thrombin-promoted invasion is inhibited by hirudin. Stimulation of invasion is a receptor-mediated process that is mimicked by a thrombin receptor-activating peptide. Thrombin has no effect on chemotaxis in vitro. Thrombin receptor is detectable on the surface of MDA-MB231 cells, but not on the other two cell lines. Introduction of oestrogen receptors into MDA-MB231 cells by transfection with pHEO had no effect on thrombin receptor expression, in the presence or absence of oestradiol. This paper demonstrates that thrombin increases invasion by the aggressive breast cancer cell line MDA-MB231 by a thrombin receptor-dependent mechanism.  (+info)

Similarities and differences in RANTES- and (AOP)-RANTES-triggered signals: implications for chemotaxis. (4/5128)

Chemokines are a family of proinflammatory cytokines that attract and activate specific types of leukocytes. Chemokines mediate their effects via interaction with seven transmembrane G protein-coupled receptors (GPCR). Using CCR5-transfected HEK-293 cells, we show that both the CCR5 ligand, RANTES, as well as its derivative, aminooxypentane (AOP)- RANTES, trigger immediate responses such as Ca2+ influx, receptor dimerization, tyrosine phosphorylation, and Galphai as well as JAK/STAT association to the receptor. In contrast to RANTES, (AOP)-RANTES is unable to trigger late responses, as measured by the association of focal adhesion kinase (FAK) to the chemokine receptor complex, impaired cell polarization required for migration, or chemotaxis. The results are discussed in the context of the dissociation of the late signals, provoked by the chemokines required for cell migration, from early signals.  (+info)

Chemotactic responses of Escherichia coli to small jumps of photoreleased L-aspartate. (5/5128)

Computer-assisted motion analysis coupled to flash photolysis of caged chemoeffectors provides a means for time-resolved analysis of bacterial chemotaxis. Escherichia coli taxis toward the amino acid attractant L-aspartate is mediated by the Tar receptor. The physiology of this response, as well as Tar structure and biochemistry, has been studied extensively. The beta-2, 6-dinitrobenzyl ester of L-aspartic acid and the 1-(2-nitrophenyl)ethyl ether of 8-hydroxypyrene-1,3,6-tris-sulfonic acid were synthesized. These compounds liberated L-aspartate and the fluorophore 8-hydroxypyrene 1,3,6-tris-sulfonic acid (pyranine) upon irradiation with near-UV light. Photorelease of the fluorophore was used to define the amplitude and temporal stability of the aspartate jumps employed in chemotaxis experiments. The dependence of chemotactic adaptation times on aspartate concentration, determined in mixing experiments, was best fit by two Tar aspartate-binding sites. Signal processing (excitation) times, amplitudes, and adaptive recovery of responses elicited by aspartate jumps producing less than 20% change in receptor occupancy were characterized in photorelease assays. Aspartate concentration jumps in the nanomolar range elicited measurable responses. The response threshold and sensitivity of swimming bacteria matched those of bacteria tethered to glass by a single flagellum. Stimuli of similar magnitude, delivered either by rapid mixing or photorelease, evoked responses of similar strength, as assessed by recovery time measurements. These times remained proportional to change in receptor occupancy close to threshold, irrespective of prior occupancy. Motor excitation responses decayed exponentially with time. Rates of excitation responses near threshold ranged from 2 to 7 s-1. These values are consistent with control of excitation signaling by decay of phosphorylated pools of the response regulator protein, CheY. Excitation response rates increased slightly with stimulus size up to values limited by the instrumentation; the most rapid was measured to be 16 +/- 3 (SE) s-1. This increase may reflect simultaneous activation of CheY dephosphorylation, together with inhibition of its phosphorylation.  (+info)

Tn5-induced and spontaneous switching of Sinorhizobium meliloti to faster-swarming behavior. (6/5128)

Tn5 mutants of Sinorhizobium meliloti RMB7201 which swarmed 1.5 to 2. 5 times faster than the parental strain in semisolid agar, moist sand, and viscous liquid were identified. These faster-swarming (FS) mutants outgrew the wild type 30- to 40-fold within 2 days in mixed swarm colonies. The FS mutants survived and grew as well as or better than the wild type under all of the circumstances tested, except in a soil matrix subjected to air drying. Exopolysaccharide (EPS) synthesis was reduced in each of the FS mutants when they were grown on defined succinate-nitrate medium, but the extent of reduction was different for each. It appears that FS behavior likely results from a modest, general derepression of motility involving an increased proportion of motile and flagellated cells and an increased average number of flagella per cell and increased average flagellar length. Spontaneous FS variants of RMB7201 were obtained at a frequency of about 1 per 10,000 to 20,000 cells by either enrichment from the periphery of swarm colonies or screening of colonies for reduced EPS synthesis on succinate-nitrate plates. The spontaneous FS variants and Tn5 FS mutants were symbiotically effective and competitive in alfalfa nodulation. Reversion of FS variants to wild-type behavior was sporadic, indicating that reversion is affected by unidentified environmental factors. Based on phenotypic and molecular differences between individual FS variants and mutants, it appears that there may be multiple genetic configurations that result in FS behavior in RMB7201. The facile isolation of spontaneous FS variants of Escherichia coli and Pseudomonas aeruginosa indicates that switching to FS behavior may be fairly common among bacterial species. The substantial growth advantage of FS mutants and variants wherever nutrient gradients exist suggests that switching to FS forms may be an important behavioral adaptation in natural environments.  (+info)

Sperm chemotaxis. (7/5128)

Communication between spermatozoa and egg before contact by chemotaxis appears to be prevalent throughout the animal kingdom. In non-mammalian species, sperm chemotaxis to factors secreted from the egg is well documented. In mammals, sperm chemotaxis to follicular factors in vitro has been established in humans and mice. The attractants of female origin in non-mammalian species are heat-stable peptides or proteins of various sizes, or other small molecules, depending on the species. Species specificity of the attractants in non-mammalian species may vary from high species specificity, through specificity to families with no specificity within a family, to absence of specificity. The mammalian sperm attractants have not been identified but they appear to be heat-stable peptides. The claim that progesterone is the attractant for human spermatozoa has failed to be substantiated, neither have claims for other mammalian sperm attractants been verified. The molecular mechanism of sperm chemotaxis is not known. Models involving modulation of the intracellular Ca2+ concentration have been proposed for both mammalian and non-mammalian sperm chemotaxis. The physiological role of sperm chemotaxis in non-mammalian species appears to differ from that in mammals. In non-mammalian species, sperm chemotaxis strives to bring as many spermatozoa as possible to the egg. However, in mammals, the role appears to be recruitment of a selective population of capacitated ('ripe') spermatozoa to fertilize the egg.  (+info)

Cloning and characterization of chemotaxis genes in Pseudomonas aeruginosa. (8/5128)

Two chemotaxis-defective mutants of Pseudomonas aeruginosa, designated PC3 and PC4, were selected by the swarm plate method after N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis. These mutants were not complemented by the P. aeruginosa cheY and cheZ genes, which had been previously cloned (Masduki et al., J. Bacteriol., 177, 948-952, 1995). DNA sequences downstream of the cheY and cheZ genes were able to complement PC3 but not PC4. Sequence analysis of a 9.7-kb region directly downstream of the cheZ gene found three chemotaxis genes, cheA, cheB, and cheW, and seven unknown open reading frames (ORFs). The predicted translation products of the cheA, cheB, and cheW genes showed 33, 36, and 31% amino acid identity with Escherichia coli CheA, CheB, and CheW, respectively. Two of the unknown ORFs, ORF1 and ORF2, encoded putative polypeptides that resembled Bacillus subtilis MotA (40% amino acid identity) and MotB (34% amino acid identity) proteins, respectively. Although P. aeruginosa was found to have proteins similar to the enteric chemotaxis proteins CheA, CheB, CheW, CheY, and CheZ, the gene encoding a CheR homologue did not reside in the chemotaxis gene cluster. The P. aeruginosa cheR gene could be cloned by phenotypic complementation of the PC4 mutant. This gene was located at least 1,800 kb away from the chemotaxis gene cluster and encoded a putative polypeptide that had 32% amino acid identity with E. coli CheR.  (+info)

Several methods for detecting or measuring negative chemotaxis are described. Using these, we have surveyed a number of chemicals for their ability to repel Escherichia coli. Although most of the repellents are harmful compounds, harmfulness is neither necessary nor sufficient to make a compound a repellent. The repellents can be grouped into at least nine classes according to (i) competition experiments, (ii) mutants lacking certain of the negative taxes, and (iii) their chemical structure. The specificity of each class was studied. It is suggested that each class corresponds to a distinct chemoreceptor. Generally, non-chemotactic mutants lack both positive and negative chemotaxis, and l-methionine is required for both kinds of taxis. Repellents at very low concentrations are not attractants, and attractants at very high concentrations are not repellents. ...
The Escherichia coli chemotaxis network is a model system for biological signal processing. In E. coli, transmembrane receptors responsible for signal transduction assemble into large clusters containing several thousand proteins. These sensory clusters have been observed at cell poles and future division sites. Despite extensive study, it remains unclear how chemotaxis clusters form, what controls cluster size and density, and how the cellular location of clusters is robustly maintained in growing and dividing cells. Here, we use photoactivated localization microscopy (PALM) to map the cellular locations of three proteins central to bacterial chemotaxis (the Tar receptor, CheY, and CheW) with a precision of 15 nm. We find that cluster sizes are approximately exponentially distributed, with no characteristic cluster size. One-third of Tar receptors are part of smaller lateral clusters and not of the large polar clusters. Analysis of the relative cellular locations of 1.1 million individual proteins
TY - JOUR. T1 - Sensitivity, cooperativity and gain in chemotaxis signal transduction. AU - Stock, J.. N1 - Funding Information: We thank M. Levit, B. Bassler, A. Newton, U. Alon and T. Silhavy for helpful discussions. This work was supported by Public Health Service research grant GM57773. PY - 1999. Y1 - 1999. KW - Bacteria. KW - Chemotaxis. KW - E.coli. KW - Microbiology. KW - Receptor. KW - Salmonella. KW - Sensory motor. UR - http://www.scopus.com/inward/record.url?scp=0032971990&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0032971990&partnerID=8YFLogxK. U2 - 10.1016/S0966-842X(98)01429-2. DO - 10.1016/S0966-842X(98)01429-2. M3 - Short survey. C2 - 10068988. AN - SCOPUS:0032971990. VL - 7. SP - 1. EP - 4. JO - Trends in Microbiology. JF - Trends in Microbiology. SN - 0966-842X. IS - 1. ER - ...
Abstract The two-component based chemotaxis signal transduction system allows flagellated bacteria to sense their surrounding chemical environment and move towards more favorable conditions. The attractant signals can be sensed by transmembrane chemoreceptors, and then transmitted to the histidine kinase CheA. Once activated, CheA interacts with the response regulator CheY through phosphorelay, which causes a change in the rotation of the flagella. The direction of flagella rotation determines whether a cell swims straight or just tumbles. Cells also need adaptation to respond to a change in chemical concentrations, and return to their prestimulated level. Adaptation in the B. subtilis chemotaxis system is achieved by three coordinated systems: the methylation system, the CheC/CheD/CheY-p system and the CheV system. CheD, the previously identified receptor deamidase, was shown to be critical to the ability of B. subtilis to perform chemotaxis and is the main focus of this study. This study ...
Sensory adaptation by the chemotaxis system of Escherichia coli requires adjustments of the extent of methyl esterification of the chemotaxis receptor proteins. One mechanism utilized by E. coli to make such adjustments is to control the activity of CheB, the enzyme responsible for removing receptor methyl ester groups. Previous work has established the existence of a multicomponent signal transduction pathway that enables the chemotaxis receptor proteins to control the methylesterase activity in response to chemotactic stimuli. We isolated and characterized CheB mutants that do not respond normally to this control mechanism. In intact cells these CheB variants could not be activated in response to negative chemotaxis stimuli. Further characterization indicated that these CheB variants could not be phosphorylated by the chemotaxis protein kinase CheA. Disruption of the mechanism responsible for regulating methylesterase activity was also observed in cells carrying chromosomal deletions of either cheA or
Rhodobacter sphaeroides has multiple homologues of most of the Escherichia coli chemotaxis genes, organized in two major operons and other, unlinked, loci. These include cheA1 and cheW1 (che Op1) and cheA2, cheW2 and cheW3 (che Op2). We have deleted each of these cheA and cheW homologues in-frame and examined the chemosensory behaviour of these strains on swarm plates and in tethered cell assays. In addition, we have examined the effect of these deletions on the polar localization of the chemoreceptor McpG. In E. coli, deletion of either cheA or cheW results in a non-chemotactic phenotype, and these strains also show no receptor clustering. Here, we demonstrate that CheW2 and CheA2 are required for the normal localization of McpG and for normal chemotactic responses under both aerobic and photoheterotrophic conditions. Under aerobic conditions, deletion of cheW3 has no significant effect on McpG localization and only has an effect on chemotaxis to shallow gradients in swarm plates. Under
Specific glutamates in the methyl-accepting chemotaxis proteins (MCPs) of Escherichia coli are modified during sensory adaptation. Attractants that bind to MCPs are known to increase the rate of receptor modification, as with serine and the serine receptor (Tsr), which contributes to an increase in the steady-state (adapted) methylation level. However, MCPs form ternary complexes with two cytoplasmic signaling proteins, the kinase (CheA) and an adaptor protein (CheW), but their influences on receptor methylation are unknown. Here, the influence of CheW on the rate of Tsr methylation has been studied to identify contributions to the process of adaptation. Methyl group incorporation was measured in a series of membrane samples in which the Tsr molecules were engineered to have one available methyl-accepting glutamate residue (297, 304, 311 or 493). The relative rates at these sites (0.14, 0.05, 0.05 and 1, respectively) differed from those found previously for the aspartate receptor (Tar), which was in
Specific glutamates in the methyl-accepting chemotaxis proteins (MCPs) of Escherichia coli are modified during sensory adaptation. Attractants that bind to MCPs are known to increase the rate of receptor modification, as with serine and the serine receptor (Tsr), which contributes to an increase in the steady-state (adapted) methylation level. However, MCPs form ternary complexes with two cytoplasmic signaling proteins, the kinase (CheA) and an adaptor protein (CheW), but their influences on receptor methylation are unknown. Here, the influence of CheW on the rate of Tsr methylation has been studied to identify contributions to the process of adaptation. Methyl group incorporation was measured in a series of membrane samples in which the Tsr molecules were engineered to have one available methyl-accepting glutamate residue (297, 304, 311 or 493). The relative rates at these sites (0.14, 0.05, 0.05 and 1, respectively) differed from those found previously for the aspartate receptor (Tar), which was in
CP002355.PE262 Location/Qualifiers FT CDS_pept 251606..252700 FT /codon_start=1 FT /transl_table=11 FT /locus_tag=Sulku_0263 FT /product=methyl-accepting chemotaxis sensory transducer FT /note=COGs: COG0840 Methyl-accepting chemotaxis protein; FT InterPro IPR004090: IPR004089; KEGG: cla:Cla_1032 FT MCP-domain signal transduction protein; PFAM: chemotaxis FT sensory transducer; SMART: chemotaxis sensory transducer; FT SPTR: Methyl-accepting chemotaxis protein; PFAM: FT Methyl-accepting chemotaxis protein (MCP) signaling domain; FT Myosin-like coiled-coil protein FT /db_xref=EnsemblGenomes-Gn:Sulku_0263 FT /db_xref=EnsemblGenomes-Tr:ADR32930 FT /db_xref=GOA:E4TY17 FT /db_xref=InterPro:IPR004089 FT /db_xref=InterPro:IPR004090 FT /db_xref=InterPro:IPR025991 FT /db_xref=UniProtKB/TrEMBL:E4TY17 FT /protein_id=ADR32930.1 FT /translation=MGWFSDDTELKEELSVLQKENTALRDENQELARKLQECEAKIAKE FT DERHRCENASMIMTYQNEQLKKNLVDVQGNMASSVASSKENIAQSTALLENIVELGQKA FT ...
antibody-antibodies.com is the marketplace for research antibodies. Find the right antibody for your research needs. CobB regulates Escherichia coli chemotaxis by deacetylating the response regulator CheY.
The bacterial chemotaxis receptors are transmembrane receptors with a simple signalling pathway which has elements relevant to the general understanding of signal recognition and transduction across membranes, how signals are relayed between molecules in a pathway, and how adaptation to a persistent signal is achieved. Bacterial chemotaxis receptors are composed of a ligand-binding domain, a transmembrane domain consisting of two helices TM1 and TM2, and a cytoplasmic domain. All known bacterial chemotaxis receptors have a highly conserved cytoplasmic domain, which unites signals from different ligand domains into a single signalling pathway to flagella motors. ...
Monocyte adhesion and migration to the subendothelial space represent critical steps in atherogenesis. Here, we investigated whether extracts from the aerosol of a prototypic modified risk tobacco product (pMRTP), based on heating rather than combusting tobacco, exhibited differential effects on the migratory behavior of monocytes compared with that from the reference cigarette, 3R4F. THP-1 cells, a monocytic cell line, and human coronary arterial endothelial cells (HCAECs) were used to investigate chemotaxis and transendothelial migration (TEM) of monocytes in conventional and impedance-based systems. THP-1 cells migrated through a monolayer of HCAECs in response to C-X-C motif ligand 12 (CXCL12), a chemokine involved in diverse cellular functions including chemotaxis and survival of stem cells. Treatment of THP-1 cells with extracts from 3R4F or pMRTP induced concentration-dependent increases in cytotoxicity (7-aminoactinomycin D), and inflammation (IL-8 and TNF-α). CXCL12-mediated chemotaxis ...
Chemotaxis (from chemo- + taxis) is the movement of an organism in response to a chemical stimulus. Somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment. This is important for bacteria to find food (e.g., glucose) by swimming toward the highest concentration of food molecules, or to flee from poisons (e.g., phenol). In multicellular organisms, chemotaxis is critical to early development (e.g., movement of sperm towards the egg during fertilization) and subsequent phases of development (e.g., migration of neurons or lymphocytes) as well as in normal function. In addition, it has been recognized that mechanisms that allow chemotaxis in animals can be subverted during cancer metastasis. Positive chemotaxis occurs if the movement is toward a higher concentration of the chemical in question; negative chemotaxis if the movement is in the opposite direction. Chemically prompted kinesis (randomly directed or ...
Neutrophils play a critical role in host defense against invading pathogens. Chemotaxis, the directed migration of cells, allows neutrophil to seek out the sites of inflammation and infection. Neutrophil chemotaxis as well as other type of cell migration are considered as cycles composed of highly orchestrated steps. Recently the underlying signaling mechanisms of neutrophil chemotaxis are better understood with the studies in knockout mice and neutrophil-like cell lines: a number of signaling molecules in neutrophil chemotaxis have been identified, and a feedback loop-based model of frontness and backness pathways has been proposed to explain the establishment of neutrophil polarity and chemotaxis. However, the signaling mechanisms that control actin cytoskeleton reorganization and interaction between the cells and the substratum on which cells migrate are still not fully understood. In my first research project, we have identified a signaling pathway, mediated by non-receptor tyrosine ...
In this talk, I will first discuss several chemotaxis models includingthe classical Keller-Segel model.Chemotaxis is the phenomenon in which cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals (chemoattractants) in their environment. The mathematical models of chemotaxis are usually described by highly nonlinear time dependent systems of PDEs. Therefore, accurate and efficient numerical methods are very important for the validation and analysis of these systems. Furthermore, a common property of all existing chemotaxis systems is their ability to model a concentration phenomenon that mathematically results in solutions rapidly growing in small neighborhoods of concentration points/curves. The solutions may blow up or may exhibit a very singular, spiky behavior. In either case, capturing such solutions numerically is a challenging problem. In our work we propose a family of stable (even at times near blow up) and highly accurate ...
Shop Probable chemotaxis response regulator protein-glutamate methylesterase ELISA Kit, Recombinant Protein and Probable chemotaxis response regulator protein-glutamate methylesterase Antibody at MyBioSource. Custom ELISA Kit, Recombinant Protein and Antibody are available.
TY - JOUR. T1 - Phosphodiesterase inhibitor attenuation of fibroblast chemotaxis depends on endogenous prostaglandin production. AU - Kohyama, T.. AU - Liu, X.. AU - Zhu, Y.. AU - Wen, F. Q.. AU - Wang, H.. AU - Rennard, S. I.. PY - 2001. Y1 - 2001. UR - http://www.scopus.com/inward/record.url?scp=0034923305&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0034923305&partnerID=8YFLogxK. U2 - 10.1378/chest.120.1_suppl.S14. DO - 10.1378/chest.120.1_suppl.S14. M3 - Article. AN - SCOPUS:0034923305. VL - 120. SP - 14S-15S. JO - Chest. JF - Chest. SN - 0012-3692. IS - SUPPL.. ER - ...
APL-1 overexpression using either the apl-1 or the snb-1 promoter, but not the pan-neuronal rab-3 promoter, caused a diminished chemotaxis response to both sodium acetate and benzaldehyde. Similarly, a short heat shock during adulthood to induce ubiquitous APL-1 expression was sufficient to cause an impaired chemotaxis response. These results suggest that APL-1 expression in non-neuronal cells decreases or disrupts the chemotaxis response. For instance, apl-1 signaling may interfere with the feedback from downstream neurons or non-neuronal tissue to the sensory neurons. Strikingly, the chemotaxis impairments of these transgenic animals were fully or partially restored by decreased activity of daf-2 insulin-IGF-1 receptor, daf-7 TGFβ, or daf-12 NHR signaling. Hence, the effects of APL-1 levels on chemotaxis are unlikely to be due to disrupted neuronal structure or neurodegeneration, but rather to modulation of the insulin/IGF-1 and/or DAF-12 NHR signaling pathways. Similarly, disruption of apl-1 ...
The main finding of the current study is that effector CD8+ T cells in skin epithelium approach clusters of infected cells by subtle chemotaxis. This directed migration can be described as a small preference for movements toward the microlesion in an otherwise highly irregular trajectory, and in fact the T cells move away from the sites of infection almost as often as they move toward it.. The observed CXCR3-mediated attraction of T cells by clusters of infected cells implies the existence of a chemoattractant gradient, and the finding that the strength of T cell attraction correlates with lesion size is also consistent with this notion. If T cells are guided to sites of infection by a gradient, why is their migration pattern so erratic? One explanation is that T cell migration has to occur through a bed of tightly linked keratinocytes, thereby severely limiting the number of potential trajectories. This, however, does not seem to explain why T cells also frequently move away from the site of ...
p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.,/p> ,p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.,/p> ,p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).,/p> ,p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x,sup>64,/sup> + x,sup>4,/sup> + x,sup>3,/sup> + x + 1. The algorithm is described in the ISO 3309 standard. ,/p> ,p class=publication>Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.,br /> ,strong>Cyclic redundancy and other checksums,/strong>,br /> ,a href=http://www.nrbook.com/b/bookcpdf.php>Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993),/a>),/p> Checksum:i ...
p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.,/p> ,p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.,/p> ,p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).,/p> ,p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x,sup>64,/sup> + x,sup>4,/sup> + x,sup>3,/sup> + x + 1. The algorithm is described in the ISO 3309 standard. ,/p> ,p class=publication>Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.,br /> ,strong>Cyclic redundancy and other checksums,/strong>,br /> ,a href=http://www.nrbook.com/b/bookcpdf.php>Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993),/a>),/p> Checksum:i ...
UNLABELLED: Chemokines (CK) provide directional cues that mediate the recruitment of leukocytes to sites of inflammation. Broad-spectrum blockade of the CC-CK family, using the vaccinia virus 35K protein, has been shown to cause a potent reduction of systemic inflammation in models of atherosclerosis, vein graft disease and arthritis. We have used a cell membrane-targeted form of 35K, Mem35K, to probe whether cell-associated blockade of chemokine response is sufficient to reduce cell recruitment in inflammation. In Tie2cre mice, activation of a flox-stop Mem35K transgene directed conditional expression of Mem35K in leukocytes and endothelial cells, confirmed by Western blotting, flow cytometry and immunofluorescence microscopy. This conditional Mem35K expression was sufficient to increase cell surface CCL5 binding and reduce chemotaxis in vitro to CCL5, CCL2 and CCL3 but not to non-CC-CK chemoattractants, LTB4, C5a or chemerin. However, in vivo monocyte recruitment into the peritoneum driven by zymosan
During gastrulation in amniotes, epiblast cells ingress through the primitive streak and migrate away to form endodermal, mesodermal, and extraembryonic structures. Here we analyze the detailed movement trajectories of cells emerging at different anterior-posterior positions from the primitive strea …
Predicted to have Roundabout binding activity and heparin binding activity. Predicted to be involved in axon guidance and negative chemotaxis. Predicted to localize to the integral component of ... Predicted to have Roundabout binding activity and heparin binding activity. Predicted to be involved in axon guidance and negative chemotaxis. Predicted to localize to the integral component of membrane. Is expressed in cardiovascular system; hematopoietic system; ventral mesoderm; and yolk syncytial layer. Orthologous to human LRRC15 (leucine rich repeat containing 15). ...
The neural basis of chemotaxis in C. elegans has been studied for years. As sensory inputs, the responses of neurons to chemical cues, such as odor and salts, have been well described (Chalasani et al., 2007; Suzuki et al., 2008). As behavioral outputs, two major strategies for chemotaxis are known: (1) klinokinesis, in which the animal changes the frequency of a complex turning behavior that consists of consecutive short reversals and omega turns, and (2) klinotaxis, in which the animal gradually curves during forward locomotion in response to the chemical gradient perpendicular to the body axis (Pierce-Shimomura et al., 1999; Iino and Yoshida, 2009).. Recent studies on chemotaxis to odor have provided a better understanding of the neural mechanisms that connect these sensory inputs to behavioral outputs. AWC chemosensory neurons show calcium responses to the removal of odor, such as isoamyl alcohol or butanone (Chalasani et al., 2007). Three major interneuron classes that are postsynaptic to ...
One assay that deserves to be explain is the Multi-capillary assay. It uses 96-well PVC microplates as chemotaxis chamber and 1μl glass capillaries. You can see a picture of it in figure 4, at the left. We designed this chemotaxis assay when we were looking for a good way to perform numerous and simultaneous capillary assays. The assembly of the assay required to make holes in a microplate lid to allow glass capillaries to go through it. The lid is put upside down over the microplate and it is filled with 2% agarose gel. We also used parafilm to avoid that the gel drip through the lid holes while it was still humid. The function of the gel is to hold capillaries, in its dry way. In orther to fill capillaries we closed one of its ends by heating and heated the glass; then it was introduce in a attractant or buffer suspension and automatically it is filled. It is important to introduce the capillaries in the lid and gel by its closed end to keep the sterility on the other end. Then it is only ...
One assay that deserves to be explain is the Multi-capillary assay. It uses 96-well PVC microplates as chemotaxis chamber and 1μl glass capillaries. You can see a picture of it in figure 4, at the left. We designed this chemotaxis assay when we were looking for a good way to perform numerous and simultaneous capillary assays. The assembly of the assay required to make holes in a microplate lid to allow glass capillaries to go through it. The lid is put upside down over the microplate and it is filled with 2% agarose gel. We also used parafilm to avoid that the gel drip through the lid holes while it was still humid. The function of the gel is to hold capillaries, in its dry way. In orther to fill capillaries we closed one of its ends by heating and heated the glass; then it was introduce in a attractant or buffer suspension and automatically it is filled. It is important to introduce the capillaries in the lid and gel by its closed end to keep the sterility on the other end. Then it is only ...
In 1975 our laboratory reported that a methylated membrane protein is involved in bacterial chemotaxis (Kort et al., 1975). It is now known that the extent of methylation of this protein (called MCP...
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Abstract: In recent years, it has been drawn a lot of attention to the question of whether logistic kinetics is sufficient to enforce the global existence of classical solutions or to prevent finite-time blow-up in various chemotaxis models. However, for several important chemotaxis models, only in the space two dimensional setting, it has been shown that logistic kinetics is sufficient to enforce the global existence of classical solutions (see [8] and [28]). The current paper is to give a confirmed answer to the above question for the following parabolic-elliptic chemotaxis system with singular sensitivity and logistic source in any space dimensional setting, \begin{equation} \begin{cases} u_t=\Delta u-\chi\nabla\cdot (\frac{u}{v} \nabla v)+u(a(x,t)-b(x,t) u),\quad x\in \Omega\cr 0=\Delta v-\mu v+\nu u,\quad x\in \Omega \quad \cr \frac{\partial u}{\partial n}=\frac{\partial v}{\partial n}=0,\quad x\in\partial\Omega, \end{cases} \end{equation} where $\Omega \subset \mathbb{R}^n$ is a bounded ...
In article ,9411040146.AA25636 at eliris.med.yale.edu,, lolis at ELIRIS.MED.YALE.EDU (elias lolis) wrote: , Does anyone have any strong opinions on what the most effective apparatus is , for doing neutrophil chemotaxis assays? The Boyden-chamber seems to be , heavily used but there appear to be other systems that do the job. Specifically, , does anyone know the relative advantages/disadvantages of using the 48-well , microchamber from Neuroprobe or any of the products sold by Costar. I am , a protein biochemist who will shortly set up to do these chemotaxis assays , (Ive never done them before) and any help or references would be appreciated. , , Elias Dear Elias, The Costar transwells are small, relatively cheap, disposable items. It is possible to culture cells on the filters and observe penetration through the monolayer. They are simple to set up but use a lot of solutions and require you to cut out each filter from the frame by hand, which is quite a pain. I dont know if Costar has ...
To date, we have not tested the fixation of cells in gel inside the observation area of µ-Slide Chemotaxis. From tube formation assays, we generally know that fixation, permeabilization, blocking, and staining of cells on Matrigel™ is possible. Therefore, it should also be possible to do immunostainings in the 3D chemotaxis assay. In this case, we recommend removing the liquid from one reservoir and successively filling the second reservoir with the different solutions. We can assume that the incubation time should be increased by a factor of 4, in order to give the solutions sufficient time to diffuse into the observation area. The filling of liquids should be carefully done, in order not to push out the gel from the observation area.. ...
TY - JOUR. T1 - Mechanisms of amoeboid chemotaxis. T2 - An evaluation of the cortical expansion model. AU - Condeelis, J.. AU - Bresnick, A.. AU - Demma, M.. AU - Dharmawardhane, S.. AU - Eddy, R.. AU - Hall, A. L.. AU - Sauterer, R.. AU - Warren, V.. PY - 1990. Y1 - 1990. N2 - In this work we evaluate the cartical expansion model for amoeboid chemo‐taxis with regard to new information about molecular events in the cytoskeleton following chemo‐tactic stimulation of Dictyostelium amoebae. A rapid upshift in the concentration of chemoattrac‐tant can be used to synchronize the motile behavior of a large population of cells. This synchrony presents an opportunity to study the biochemical basis of morphological changes such as pseudopod extension that are required for amoeboid chemotaxis. Changes in the composition and activity of the cytoskeleton following stimulation can be measured with precision and correlated with important morphological changes. Such studies demonstrate that activation of ...
We consider a model for two species interacting through chemotaxis in such a way that each species produces a signal which directs the respective motion of the other. Specifically, we shall be concerned with nonnegative solutions of the Neumann problem, posed in bounded domains $\Omega\subset \mathbb{R}^n$ with smooth boundary, for the system $$\begin{cases} u_t= \Delta u - \chi \nabla \cdot (u\nabla v), & x\in \Omega, \, t|0, \\ 0=\Delta v-v+w, & x\in \Omega, \, t|0, \qquad (\star)\\ w_t= \Delta w - \xi \nabla \cdot (w\nabla z), & x\in \Omega, \, t|0, \\ 0=\Delta z-z+u, & x\in \Omega, \, t|0, \end{cases}$$ |br| with parameters $\chi \in \{\pm 1\}$ and $\xi\in \{\pm 1\}$, thus allowing the interaction of either attraction-repulsion, or attraction-attraction, or repulsion-repulsion type. |br| It is shown that |br| $\bullet$ in the attraction-repulsion case $\chi=1$ and $\xi=-1$, if $n\le 3$ then for
We show in this report that E. coli remodels its chemosensory physiology as a response to swarming. The altered physiology is likely the result of an elevation of the concentration of CheZ, which increases CheY∼P dephosphorylation bias and reduces the cells tumble bias. Reducing the tumble bias improves swarming performance, but a very low tumble bias negatively impacts expansion of the swarm, corroborating previous reports that tumbling is still necessary in the swarm (49). Therefore, there is an optimal tumble bias for swarming and E. coli is able to adapt its motility behavior to surface conditions that favor swarming.. The increased stability of CheZ in swarmer cells explains the increase in their CheZ levels (Fig. 6). However, the mechanism by which CheZ is specifically stabilized during swarming will require further investigation. In B. subtilis, contact with swarm agar increases synthesis of flagella by somehow sequestering a specific adaptor protein that otherwise (in liquid), in ...
Lamb, DJ, Modjtahedi, H, Plant, NJ and Ferns, GAA (2004) EGF mediates monocyte chemotaxis and macrophage proliferation and EGF receptor is expressed in atherosclerotic plaques ...
The Laboratory of Cellular and Molecular Biology (LCMB) has a long and distinguished history in the study of signal transduction mechanisms that control normal cell growth and, when altered, lead to malignant transformation. Through the 1980s and 1990s many critical signaling molecules including growth factors, growth factor receptors and intracellular transduction molecules were first identified and characterized in the LCMB. The mission of LCMB remains focused on performing cutting-edge, world-class research in this field of biology, and important discoveries continue. The goals of the six LCMB investigators cover a wide range of questions. They focus on defining signaling components and pathways and understanding their regulation. The relationship of signaling to cellular growth and death, transcriptional regulation, mitosis, cellular differentiation and organogenesis, cell adhesion, motility and chemotaxis are more complex topics under investigation. Alterations in signaling leading to ...
Signalling interactions between gametes are fundamental for sex. They entail both diffusible and surface bound signals that serve for partner attraction and recognition, and gamete communication during fusion [26,53-55]. These interactions are nearly always asymmetric so that gametes send and receive signals in a mating-type- or sex-specific manner. In this work, we ask whether asymmetric signalling enhances the efficiency of the signalling interaction itself, a theory first proposed in the 1980s [23].. Some general principles emerge from our analysis. Non-chemotactic cells can improve their search for a partner when they move in fixed directions for longer periods of time (high persistence, figure 3a). That straight-line movement can optimize a random search has been shown before in a different context (see Li et al. and references therein [33]). When cells are unable to maintain a fixed directionality for prolonged periods, symmetric chemotaxis (all cells send and receive the same signal) can ...
Cell migration and invasion are live cell kinetic assays useful in oncology research. The principle difference between migration and invasion is that migration refers to normal cell movement; whereas invasion describes cells actively invading surrounding tissue. It can do this under the influence of a chemoattractant gradient and secretion of proteases.
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We study a kinetic model for chemotaxis introduced by Othmer, Dunbar, and Alt [23], which was motivated by earlier results of Alt, presented in [1], [2]. In two papers by Chalub, Markowich, Perthame and Schmeiser, it was rigorously shown that, in three dimensions, this kinetic model leads to the classical Keller-Segel model as its drift-diffusion limit when the equation of the chemo-attractant is of elliptic type [4], [5]. As an extension of these works we prove that such kinetic models have a macroscopic diffusion limit in both two and three dimensions also when the equation of the chemo-attractant is of parabolic type, which is the original version of the chemotaxis model.
Used to investigate chemotaxis of fast or slow migrating adherent cells and non-adherent cells in gel matrices Chemotaxis measurement in real-time Stable gra...
The in-cylinder tumble intensity of GDI engine is crucial to combustion stability and thermal efficiency, required to be different for the different operation conditions. A new variable tumble system (VTS) applied to GDI engine was introduced to meet tumble ratio requirements in various situations. The transient gas exchange of four combustion systems all were investigated during both intake and compression strokes based on CFD simulation, namely (1) Case 1-Intake port B (with flap valve)/Spherical piston crown; (2) Case 2-Intake port B (without flap valve)/Spherical piston crown; (3) Case 3- Intake port A/Spherical piston crown; (4) Case 4-Intake port A/Dented piston crown. The simulated results of dynamic tumble ratio showed that during the whole intake process the dynamic tumble ratio of Case1 was obviously higher than other Cases with the same boundary conditions, and the maximum value was about 5∼6 times higher. The crank angle range, in which the strong tumble motion fully developed, was ...
Zoom, Glück Drück, and tumble the 3D View. I have been unable to mention, much Tischkicker Löwen do justice to, all the many themes and arguments that come tumbling off the pages of this book. Wie kann ich Übersetzungen in den Vokabeltrainer übernehmen? Wollen Sie Gkfx Satz übersetzen? Lernen Sie die Übersetzung für tumble in LEOs Englisch ⇔ Deutsch Wörterbuch​. Mit Flexionstabellen der verschiedenen Fälle und Zeiten ✓ Aussprache und. Übersetzung Englisch-Deutsch für tumble im PONS Online-Wörterbuch nachschlagen! Gratis Vokabeltrainer, Verbtabellen, Aussprachefunktion. today for a Swiss household to have two television sets, several computers and a tumble dryer - all these appliances increase the electricity consumed per. tumble Bedeutung, Definition tumble: 1. to fall quickly and without control: 2. to fall a lot in value in a short time: 3. to move in. No friend of liberty can avoid the tumble back and forth between Burke and Paine. And then the convenience stores will ...
The overall movement of a bacterium is the result of alternating tumble and swim phases. If one watches a bacterium swimming in a uniform environment, its movement will look like a random walk with relatively straight swims interrupted by random tumbles that reorient the bacterium. Bacteria such as E. coli are unable to choose the direction in which they swim, and are unable to swim in a straight line for more than a few seconds due to rotational diffusion. In other words, bacteria forget the direction in which they are going. Given these limitations, it is remarkable that bacteria can direct their motion to find favorable locations with high concentrations of attractants (usually food) and avoid repellents (usually poisons). In the presence of a chemical gradient bacteria will chemotax, or direct their overall motion based on the gradient. If the bacterium senses that it is moving in the correct direction (toward attractant/away from repellent), it will keep swimming in a straight line for a ...
TY - JOUR. T1 - Evidence that the methylesterase of bacterial chemotaxis may be a serine hydrolase. AU - Krueger, Joanna K.. AU - Stock, J.. AU - Schutt, C. E.. N1 - Funding Information: We thank Dr. Jim Mottonen for his enlightenment regardingt he sequenceh omologyo f CheB with acetylcholine esterasesa nd Dr. Michael Rozyski for his invaluablea dvice and suggestionsW. e also thank Dr. Robert Gerard (University of Texas, Southwestern Medical School) for the use of his mutagenesifsa cili-ties and expertise. Thisr esearch was supportedb y grants from the National Institute of Health. Copyright: Copyright 2014 Elsevier B.V., All rights reserved.. PY - 1992/3/12. Y1 - 1992/3/12. N2 - CheB, the methylesterase of chemotactic bacteria, catalyzes the hydrolysis of glutamyl-methyl esters in bacterial chemoreceptor proteins. The two cysteines predicted by the amino acid sequence of CheB were replaced by alanine residues. The resulting mutants, Cys207-Ala, Cys309-Ala and a double cysteine mutant ...
Chemotaxis, or directed cell migration, is important in many biological processes such as embryonic development, wound healing, and the direction of immune cells to sites of inflammation or infection. When not regulated properly, chemotaxis is implicated in disease states including inflammatory diseases and cancer metastasis. During eukaryotic chemotaxis, cells are able to sense a chemical gradient through receptors on the cell membrane that trigger complicated intracellular signaling networks, ultimately resulting in changes in the actin cytoskeleton leading to cell migration. The proteins involved in these signaling networks require tight spatiotemporal regulation, and the mechanisms underlying this regulation are not well understood. The work of this dissertation aims to better elucidate the pathways that regulate chemotaxis and enable cells to respond and adapt to changes in the chemoattractant gradient. To this end, we utilized the model organism Dictyostelium discoideum, and focused on ...
Chemotaxis assays are an invaluable tool for studying the biological activity of inflammatory mediators such as CC chemokines, which have been implicated in a wide range of chronic inflammatory diseases. Conventional chemotaxis systems such as the modified Boyden chamber are limited in terms of the data captured given that the assays are analysed at a single time-point. We report the optimisation and validation of a label-free, real-time cell migration assay based on electrical cell impedance to measure chemotaxis of different primary murine macrophage populations in response to a range of CC chemokines and other chemoattractant signalling molecules. We clearly demonstrate key differences in the migratory behavior of different murine macrophage populations and show that this dynamic system measures true macrophage chemotaxis rather than chemokinesis or fugetaxis. We highlight an absolute requirement for Gαi signaling and actin cytoskeletal rearrangement as demonstrated by Pertussis toxin and
报告人简介:. Professor, Department of Microbiology and Molecular Genetics, University of California, Davis,. Editor for Applied and Environmental Microbiology(AEM). 报告摘要:. Motile bacteria have the ability tosampletheir environment and detect and move toward available growth substrates using a process called chemotaxis. Many soil bacteria are capable of degrading a wide variety of organic compounds including toxic pollutants and man-made chemicals. Chemotaxis can increase the efficiency of the biodegradation process. The most common sensory proteins used for bacterial chemotaxis are cell-surface receptors called methyl-accepting chemotaxis proteins, and the genomes of soil bacteria often harbor up to 60 chemoreceptor genes. P. putida is chemotactic to most substrates on which it is capable of growth, and it uses several different strategies to detect potential growth substrates. In this presentation it will be described and discussed that the different types of ...
Dictyostelium mutants lacking the MAP kinase DdERK2 show reduced chemotactic responses to folate and cAMP. Analysis of cAMP chemotaxis shows that Dderk2{dollar}\sp-{dollar} cells are defective in chemotaxis to high concentrations of cAMP. This defect is due to an inability to repolarize in the continued presence of high concentrations of cAMP. Under these conditions, the speed of movement of mutant cells remains low. Instead of generating a leading pseudopod, mutant cells generate transient crown-like structures over multiple regions of the cell surface. These structures differ from pseudopods in that they contain myosin II as well as F actin and coronin. These studies identify a role for MAP kinases in coordinating the formation of cell projections generated in response to chemoattractants. A polyclonal antibody against a MAP kinase (DdERK2) in Dictyostelium has been made and used to study DdERK2 activation and localization. The activation of DdERK2 by chemoattractants cAMP and folate is fast ...
Pseudomonas aeruginosa is a gram negative, rod shaped, opportunistic pathogen that is known for infecting the lungs of cystic fibrosis patients as well as burn victims. P. aeruginosa has a single flagellum located at the pole of the cell and uses chemotaxis proteins to control the flagellum which ultimately directs swimming towards or away from a stimulus. These chemotaxis proteins are localized to the pole using partitioning proteins ParP and ParC. Improper inheritance of these partitioning proteins leads to a lack of chemotaxis foci and a reduction of swimming motility. We hypothesized that Pch, a phosphodiesterase responsible for regulating c-di-GMP levels in P. aeruginosa, may interact with ParP and play a role in its function. To test our hypothesis, we assayed protein interactions between Pch and ParP using the bacterial two hybrid assay. In addition, constructs were made containing pch and parP along with fluorescence tags and protein localization was analyzed using fluorescence microscopy. The
Nitrite plays an important role in the nitrogen metabolism of most cells, including Chlamydomonas reinhardtii. We have shown that vegetative cells of C. reinhardtii are attracted by nitrite. The Nia1nit2 mutant with defects in genes encoding the nitrate reductase and regulatory protein NIT2 respectively was found to exhibit normal chemotaxis to nitrite. The data suggest that chemotaxis events appear to be specific and independent of those involved in nitrate assimilation. Unlike vegetative cells and noncompetent pregametes, mature gametes did not show chemotaxis to nitrite. Just like gamete formation, the change in chemotaxis mode is controlled by the sequential action of two environmental cues, removal of nitrogen from the medium and light. Comparative analysis of wild-type and RNAi strains with reduced level of phototropin has indicated that switch-off of chemotaxis towards nitrite is dependent on phototropin. The studies revealed individual elements of the phototropin-dependent signal transduction
Current approaches to study chemotaxis are limited by gradient instability, low throughput, cumbersome manual manipulations, high cell number requirements, inability to acquire high-content data, and/or poor data quality and reproducibility. We present here a new microfluidics-based approach to study leukocyte chemotaxis. The device features strong miniaturization of the use of cells (,12,000 cells per data point). The microfluidic channels in the device are arrayed in 96 well format and can be operated by standard liquid handling robotics or by handheld pipettors. Cells migrate along a surface in the presence of a stable gradient of chemoattractant that is maintained for at least three hours. We show the ability to obtain consistent dose response curves to chemoattractants as well as chemotactic inhibitors with the device. Because cells are microscopically accessible, the information content is high. Not only can the number of cells migrated be assessed, but also migration distances of ...
Cell migration is an essential component of most biological processes, including: immune responses, blood vessel formation, tumor metastasis, and wound healing [1]. Effective in vitro models of directed cell migration, or chemotaxis, are necessary for both basic research and drug discovery [2]. This application note describes a new methodology for studying chemotactic cell migration using the IncuCyte® ZOOM Live-Cell Imaging system. This novel approach enables real-time visualization and automated analysis of chemotactic migration in a 96-well format within a tissue culture incubator.. By incorporating a made-for-purpose, optically clear membrane into a transmembrane geometry, the IncuCyte® chemotaxis assay facilitates the label-free visualization and quantitation of directed cell migration. The design of the IncuCyte® ClearView 96-Well Cell Migration Plate ensures a stable gradient over 72 hours and requires only 1,000-5,000 cells per well. In contrast to traditional Boydenchamber ...
Chemorepulsion is the directional movement of a cell away from a substance. Of the two directional varieties of chemotaxis, chemoattraction has been studied to a much greater extent. Only recently have the key components of the chemorepulsive pathway been elucidated. The exact mechanism is still being investigated, and its constituents are currently being explored as likely candidates for immunotherapies. The mechanism of the chemorepulsion of immune cells was first acknowledged by medical researchers at the Massachusetts General Hospital in Boston in early 2002. The phenomenon was originally referred to as reverse chemotaxis, and later, fugetaxis (derived from the Latin words fugere, to flee from; and taxis, movement). For a time, the words were used interchangeably before being replaced almost exclusively by chemorepulsion. While chemorepulsion applies to all cell types, the term immunorepulsion is gaining momentum as a more specific term that only applies to hematopoietic blood cell ...
In addition to the steepness of the gradient, the context in which a cell perceives a chemoattractant gradient can have a profound effect on their response to the chemotactic stimulus. For example, both our group (Heit et al., 2005) and others (Ferguson et al., 2007) have demonstrated that neutrophil chemotaxis to fMLP is profoundly impacted by the makeup of the substratum upon which the cell is crawling. For example, ligands for LFA-1, MAC-1 and VLA-4 need to be present to get a full chemotactic response to fMLP (Heit et al., 2005). Moreover, Ferguson et al. have demonstrated profound differences in the chemotaxis of neutrophils to fMLP on glass verses protein substrata (Ferguson et al., 2007). These profound differences in the behavior of neutrophils, based on the substratum they are crawling upon, demonstrate that careful selection of the substratum is an important factor when selecting or designing chemotactic assays, especially in mammalian systems. In this regard, we have used a ...
C1q, the first component of the classical pathway of the complement system, interacts with various cell types and triggers a variety of cell-specific cellular responses, such as oxidative burst, chemotaxis, phagocytosis, etc. Different biological responses are attributed to the interaction of C1q with more than one putative cell-surface C1q receptor/C1q-binding protein. Previously, it has been shown that C1q-mediated oxidative burst by neutrophils is not linked to G-protein-coupled fMet-Leu-Phe-mediated response. In the present study, we have investigated neutrophil migration brought about by C1q and tried to identify the signal-transduction pathways involved in the chemotactic response. We found that C1q stimulated neutrophil migration in a dose-dependent manner, primarily by enhancing chemotaxis (directed movement) rather than chemokinesis (random movement). This C1q-induced chemotaxis could be abolished by an inhibitor of G-proteins (pertussis toxin) and PtdIns(3,4,5)P3 kinase (wortmannin and ...
The sequential and regulated recruitment of leukocytes into tissues by chemoattractants is essential for effective clearance of pathogens and healing. The Rho GTPases Cdc42, Rac, and Rho are important for establishing and maintaining migratory polarity. Most chemoattractants for phagocytes signal either through seven transmembrane G-protein-coupled receptors (GPCRs) or tyrosine kinase receptors. Y721 is the most important for chemotaxis because it recruits phospholipase-C-γ (PL C-γ) and the p85 subunit of class 1A PI3Ks, both of which are implicated in the initiation of chemotaxis. Several intracellular signaling complexes contribute to the polarization of phagocytes in response to chemoattractants, and they probably act together to allow optimal chemotaxis. Cdc42 is implicated in multiple types of cell polarity, including axon specification, yeast mating, and epithelial polarity. There are several PLC isoforms, of which PLCβ2 and PLCβ3 are activated by GPCR signaling in neutrophils, whereas PLCβ
Eukaryotic amoebae Dictyostelium discoideum (referred as Dictyostelium) in the vegetative state forage on bacteria by following gradients of folic acid (FA), a by-product of bacterial metabolism [1,2]. It is currently believed that Dictyostelium measure chemical gradients directly by monitoring the distribution of the occupied chemoattractant receptors. These cells can detect concentration differences as low as a few per cent across their cell bodies [3-8] and it is currently an open question what exactly limits this process. Previously, the receptor-ligand binding fluctuations were suggested as the limiting factor, which remains a possibility because a single excited receptor may amplify the signal by activating multiple G-proteins [9-11].. The chemotaxis signalling system can be described as the following Shannon communication channel [12,13]: the chemoattractant gradient direction as the input, the spatial distribution of occupied receptors as the intermediate step and the direction of cell ...
Chemotaxis is the primary mechanism by which cell movements are directed within multicellular organisms, and it is a major component of embryonic development, wound healing, and immune responses. Chemotaxis involves a complex cascade of events--formation of signaling complexes, receptor polarization, adhesion molecule activation, and cytoskeletal reorganization. Previous assay methods were limited in several ways that reduced users abilities to obtain quantitative data or to control conditions precisely. We describe a unique chemotactic assay that can incorporate multiple chemotactic gradients in different spatial and temporal combinations. In addition, this assay is easily adapted for live-cell imaging and fluorescent microscopy. With its relative simplicity, flexibility, and precision, this method is a key tool for the study of cellular chemotactic responses and the signaling processes underlying them. ...
The heterogeneity of the H460 large cell lung cancer cell line was investigated by selecting for chemokinetic cells from a CON population that demonstrated both chemokinesis and chemotaxis. Using Boyden chambers, cells that migrated under chemokinetic conditions were collected and their numbers expanded. Time-lapsed microscopy under isotropic conditions showed that KINE cells moved faster and changed directions more frequently than CON confirming their chemokinetic character. KINE cells which lacked stable focal adhesion were also less adhesive to culture plates compared to CON cells which had focal adhesions at the leading edge shown by phospho-Paxillin-tyr118 antibody labeling. Weak substrate adhesion in KINE cells may account for motile characteristics of rapid and random movement [16-19]. Furthermore, the selection for increased chemokinesis did not compromise the ability of KINE cells to chemotax. KINE cells were also significantly more invasive compared to CON.. These results underscore ...
Mathematical models of bacterial populations are often written as systems of partial differential equations for the densities of bacteria and concentrations of extracellular (signal) chemicals. This approach has been employed since the seminal work of Keller and Segel in the 1970s [Keller and Segel, J. Theor. Biol., 1971]. The system has been shown to permit travelling wave solutions which correspond to travelling band formation in bacterial colonies, yet only under specific criteria, such as a singularity in the chemotactic sensitivity function as the signal approaches zero. Such a singularity generates infinite macroscopic velocities which are biologically unrealistic. In this paper, we formulate a model that takes into consideration relevant details of the intracellular processes while avoiding the singularity in the chemotactic sensitivity. We prove the global existence of solutions and then show the existence of travelling wave solutions both numerically and analytically. ...
Studies in Dictyostelium have shown that the p110-related phosphatidylinositol-3-kinases PI3K1 and PI3K2 are required for proper development, pinocytosis chemotaxis, and chemoattractant-mediated activation of PKB. Insights into the mechanism by which PI3K regulates chemotaxis derive from studies on PKB in mammalian leukocytes and Dictyostelium cells. PKB activation requires its translocation to the plasma membrane by binding of its PH domain to PtdIns(3,4,5)P3 and PtdIns(3,4)P2 produced upon activation of PI3K, leading to PKB activation. In leukocytes and Dictyostelium cells, chemoattractants mediate PKB activation through a G-protein-coupled pathway that requires the activity of the respective PI3Ks. Chemoattractant stimulation of neutrophils and Dictyostelium cells results in a transient localization of a GFP fusion of the PH domains from the Dictyostelium and mammalian PKBs to the plasma membrane. When these cells are placed in a chemoattractant gradient, membrane localization of the ...
Chemotaxis in Pseudomonas aeruginosa.: A chemotaxis system for Pseudomonas aeruginosa was defined by using the method of Adler. Cells were attracted to compound
TY - JOUR. T1 - EXPERIMENTAL MEASUREMENT OF LEUKOCYTE RANDOM MOTILITY AND CHEMOTAXIS PARAMETERS AND THEIR DEPENDENCE UPON CHEMOATTRACTANT CONCENTRATION.. AU - Tranquillo, Robert. AU - Lauffenburger, Douglas. AU - Zigmond, Sally. PY - 1983/1/1. Y1 - 1983/1/1. UR - http://www.scopus.com/inward/record.url?scp=0020499896&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0020499896&partnerID=8YFLogxK. M3 - Conference article. AN - SCOPUS:0020499896. SP - 125. EP - 126. JO - Advances in Bioengineering, BED. JF - Advances in Bioengineering, BED. SN - 0360-9960. ER - ...
Decision making is one of the distinguishing properties of biosystems. Decision making of course does not necessarily mean conscious decision making, which is exclusively human. On the contrary, the ability to make decisions can be observed in every living organism even in unicellular species as a type of molecular logic, in the form of chemotaxis). Chemotaxis is chemistry-driven motility: towards areas of increasing concentrations of friendly chemicals (positive chemotaxis) and away from increasing concentrations of hostile chemicals (negative chmotaxis). ...
BioAssay record AID 297157 submitted by ChEMBL: Inhibition of CXCL8-induced cell migration in human PMN cells at 0.01 uM by chemotaxis assay.
An all-on-chip method enables rapid neutrophil chemotaxis assay directly from a few microliters of blood for both cell migration research and clinical sample test.
The rotation of the flagellum and the direction of movement is often regulated by sensory stimuli, allowing the cell to migrate towards attractive signals. In E.coli this is achieved through a signal transduction system that controls the phosphorylation state of the response regulator protein CheY. In the absence CheY-P the flagellum rotates CWW in a run state. The presence of CheY-P, induces a switch to CW rotation resulting in tumbling which randomly reorients the cell. When an attractant binds to a receptor it initiates a conformational change and downstream cascade that leads to suppression of CheA, a protein that normally phosphoryates CheY to CheY-P. The absence of CheY-P causes the flagellum to remain in the run state leading to migration towards the signal. A third protein, CheZ helps regulate the circuit by preventing the accumulation of CheY-P through dephosphorylation. The 2009 Imperial College of London igem team attempted to engineer e.coli chemotaxis towards malate so that ...
SUMMARY: β-Ketoadipate serves as a chemoattractant for Pseudomonas putida. The chemotactic response is inducible, and a regulatory mutant strain that forms the β-ketoadipate transport system at high levels exhibits a heightened chemotactic response to β-ketoadipate. Adipate and succinate, compounds that interact with the transport system, inhibit chemotaxis toward β-ketoadipate. Some, but not all, mutants that fail to respond chemotactically to β-ketoadipate lack the β-ketoadipate transport system. It thus appears that the transport of β-ketoadipate is associated with its function as a chemoattractant. It is likely that the metabolite attracts fluorescent Pseudomonas species to environments in which complex aromatic polymers undergo microbial dissimilation.
Fingerprint Dive into the research topics of Phosphorylation of chemoattractant receptors is not essential for chemotaxis or termination of G-protein-mediated responses. Together they form a unique fingerprint. ...
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Gradients are ubiquitous drivers of spatially differentiated behavior and communication in biological systems. For example, stripes of mRNA concentrations generated by reaction-diffusion (RD) processes in the embryo of the fruit fly Drosophila act as chemical blueprints to direct the growth of the embryo.1,2 A variety of spatial concentration patterns also arise during intercellular signaling processes.3,4 Synthetic patterns have been generated in vitro to study and control chemotaxis,5 angiogenesis,6 stem cell proliferation and differentiation,7 axon growth,8 cell culture and cell behavior in hydrogels,9,10 and protein expression.11 Chemical gradients have also been used to control reactivity, direct mechanical actuation, pattern synthetic materials and orchestrate self-regeneration.12-14 Chemical gradients are often produced using lithographic or light-driven patterning methods that encode variations of density of a molecule along a surface or within a 3-dimensional material,15-17 or by ...
Luckily, medicines can change whats missing (like insulin) or they can hindrance production of a chemical when the torso is making too much of it. The chic division close to the Access to Medicine Foundation shows which large pharmaceutical companies are marketing the most vital medicines and vaccines in the direction of the highest-burden bug in developing countries. All fluoroquinolones modestly impair puke macrophage chemotaxis (Labro 2000) and transendothelial leucocyte and monocyte migration (Uriarte et al 2004) purchase 20 mcg atrovent free shipping symptoms vs signs. DISCERN: TENS SUPPLIES READY PRO EMPIВ® CUSTOMERS We no longer conduct EmpiВ® TENS units and electrodes. We make it effortlessly representing you to boon the materiel that you are seeking next to breaking down our vast batch into categories based on the listing of injuries, Flick through online looking for peaceful medical supplies close brands, price, one of a kind offers and discounts and other categories. These are ...
Mast cells (MCs) are forceful multifunctional effector cells of the immune system. MCs are normally distributed throughout connective and mucosal tissues, but in several pathological conditions accumulation of MCs occur. This accumulation is probable due to directed migration of MCs and they are subjects for migration at least two different occations: 1) when they are recruited as progenitor cells from the blood into the tissue; and 2) when they as mature MCs are recruited to sites of inflammation. The aim of this study was to investigate MC migration to chemoattractants released in vivo or in vitro (body fluids collected from patients with asthma or rheumatoid arthritis and TH1- and TH2-cytokines) and to recombinant cytokines (transforming growth factor -β (TGF-β) and CCL5/RANTES).. This thesis shows that bronchoalveolar lavage (BAL) fluid from asthmatic patients and synovial fluid from patients with rheumatiod arthritis contain MC chemoattractants, and that part of the chemotactic activity ...
Xuehua Xu is the author of these articles in the Journal of Visualized Experiments: Imaging G-protein Coupled Receptor (GPCR)-mediated Signaling Events that Control Chemotaxis of Dictyostelium Discoideum, Imaging G Protein-coupled Receptor-mediated Chemotaxis and its Signaling Events in Neutrophil-like HL60 Cells
Chemotactic cells generate localized accumulation of phosphoinositides at the leading edge of the cell. The lipids are then bound by lipid-binding domains of various signaling proteins. Dormann et al. used fusion proteins of green fluorescent protein (GFP) with the pleckstrin homology (PH) domains of various signaling proteins to monitor localized abundance of phosphoinositides during chemotaxis or phagocytosis in Dictyostelium. The specificity of the various PH domains for binding particular phosphoinositides enabled them to compare lipid signaling during the two processes. Concentrations of phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P3] accumulated at sites of engulfment during phagocytosis, as they do at the tip of cells facing an increasing gradient of chemoattractant. During chemotaxis, the phosphatase PTEN is thought to decrease concentrations of PtdIns(3,4,5)P3, but studies with cells lacking PTEN indicated it was not providing the same function during phagocytosis. ...
BioAssay record AID 147686 submitted by ChEMBL: Compound was evaluated for the inhibition of LTB4 receptor -induced chemotaxis of isolated human neutrophils; IA means inactive.
Chemotaxis[edit]. Neutrophils undergo a process called chemotaxis via amoeboid movement, which allows them to migrate toward ... in a process called chemotaxis. They are the predominant cells in pus, accounting for its whitish/yellowish appearance.[10] ...
Bioavailability, chemotaxis, and transport of pollutants[edit]. Bioavailability, or the amount of a substance that is ... Chemotaxis, or the directed movement of motile organisms towards or away from chemicals in the environment is an important ... 2008). "Bioavailability, Chemotaxis, and Transport of Organic Pollutants". Microbial Biodegradation: Genomics and Molecular ...
However, in contrast to chemotaxis, chemokinesis has a random, non-vectorial moiety, in general. Due to the random character, ... Becker EL (1977). "Stimulated neutrophil locomotion: chemokinesis and chemotaxis". Arch Pathol Lab Med. 101 (10): 509-13. PMID ... techniques dedicated to evaluate chemokinesis are partly different from methods used in chemotaxis research. One of the most ...
Chemotaxis receptors are expressed in the surface membrane with diverse dynamics, some of them have long-term characteristics ... Kohidai L and Csaba G (1988). "Chemotaxis and chemotactic selection induced with cytokines (IL-8, RANTES and TNF alpha) in the ... Recent results proved that chemokines (e.g. IL-8, RANTES) are working on long-term chemotaxis receptors, while vasoactive ... The diverse feature of the chemotaxis receptors and ligands provides the possibility to select chemotactic responder cells with ...
Eisenbach M, Lengeler JW, Varon M, Gutnick D, Firtel FA, Omann GM, Tamada A, Murakami F (2004). Chemotaxis. River Edge, N.J: ...
Chemotaxis. Fed Proc. 1980; 39:2949-2952. 40. Stossel TP. Actin gelation and the structure and movement of cortical cytoplasm. ... Leukocyte Chemotaxis. New York: Raven Press, 1978:143-57. 27. Stossel TP. Contractile proteins in cell structure and function. ...
Chemotaxis. River Edge, N.J: Imperial College Press. ISBN 1-86094-413-2. Stackebrandt E, Dworkin M, Falkow S, Rosenberg E, ...
In contrast to the run-and-tumble model of chemotaxis associated with flagellated cells however, movement towards ... Oliveira, Nuno M.; Foster, Kevin R.; Durham, William M. (2016-06-07). "Single-cell twitching chemotaxis in developing biofilms ... Sampedro, Inmaculada; Parales, Rebecca E.; Krell, Tino; Hill, Jane E. (January 2015). "Pseudomonas chemotaxis". FEMS ... "Pseudomonas aeruginosa Twitching Motility-Mediated Chemotaxis towards Phospholipids and Fatty Acids: Specificity and Metabolic ...
Rheotaxis, thermotaxis and chemotaxis are known mechanisms that guide sperm towards the egg during the final stage of sperm ... Sperm find the eggs via chemotaxis, a type of ligand/receptor interaction. Resact is a 14 amino acid peptide purified from the ... "Molecular Mechanism for Human Sperm Chemotaxis Mediated by Progesterone". PLOS ONE. 4 (12): e8211. Bibcode:2009PLoSO...4.8211T ...
doi:10.1016/0038-0717(90)90109-D. DOI.org Gitte, Ramesh R.; Rai, P. Vittal; Patil, R. B. (1978). "Chemotaxis ofRhizobium sp. ...
He is particularly known for his work in the spontaneous appearance of order in convection, slime molds and chemotaxis. Lee ... They also developed a model for chemotaxis. Hillen and Painter say of it: "its success ... a consequence of its intuitive ... doi:10.1016/0022-5193(71)90050-6. Hillen, T.; Painter, K. J. (Jan 2009). "A user's guide to PDE models for chemotaxis. Journal ... With Evelyn Keller he developed a model for slime mold (Dictyostelium discoideum) chemotaxis that was perhaps the first example ...
Ahmed T, Shimizu TS, Stocker R (November 2010). "Microfluidics for bacterial chemotaxis". Integrative Biology. 2 (11-12): 604- ... chemotaxis and the ability to evolve / develop resistance to antibiotics in small populations of microorganisms and in a short ...
During the acute phase of inflammation, neutrophils migrate toward the site of inflammation in a process called chemotaxis, and ... chemokines that promote chemotaxis; and interferons that have anti-viral effects, such as shutting down protein synthesis in ... chemokines that promote chemotaxis; and interferons that have anti-viral effects, such as shutting down protein synthesis in ...
I. Cite uses generic title (help) Harris H (July 1954). "Role of chemotaxis in inflammation". Physiological Reviews. 34 (3): ...
Chemotaxis towards an injured cell". Antibiot. Chemother. 19: 369-81. doi:10.1159/000395442. PMID 4463832. Hu CL, Barnes FS ( ... Necrotaxis embodies a special type of chemotaxis when the chemoattractant molecules are released from necrotic or apoptotic ... Debru C. (1993). "A particular form of chemotaxis: necrotaxis. An historical view". Blood Cells. 19 (1): 5-19. PMID 8400312. ...
I. Cite uses generic title (help) Harris H (Jul 1954). "Role of chemotaxis in inflammation". Physiological Reviews. 34 (3): 529 ... fMLF proved the most potent in stimulating rabbit neutrophil chemotaxis. fMLF and a sampling of other, less potent, N-formyl ... Leukocyte chemotaxis: Methodology, physiology, clinical implications. New York.: Raven Press.CS1 maint: multiple names: authors ... release N-formyl-methionyl containing peptides with chemotactic activities that exactly mimic those of fMLF chemotaxis These ...
Other names in common use include chemotaxis-specific methylesterase, methyl-accepting chemotaxis protein methyl-esterase, CheB ... CheB is involved in chemotaxis. CheB methylesterase is responsible for removing the methyl group from the gamma-glutamyl methyl ... Kehry MR, Doak TG, Dahlquist FW (1984). "Stimulus-induced changes in methylesterase activity during chemotaxis in Escherichia ... This enzyme participates in 3 metabolic pathways: two-component system - general, bacterial chemotaxis - general, and bacterial ...
... in a process called chemotaxis. A number of variables are essential for the successful chemotaxis of neutrophils, including the ... It induces chemotaxis in target cells, primarily neutrophils but also other granulocytes, causing them to migrate toward the ... This causes the "rolling" phase of chemotaxis. Once the neutrophil is rolling along the endothelium, it will come into contact ... Köhidai L, Csaba G (1998). "Chemotaxis and chemotactic selection induced with cytokines (IL-8, RANTES and TNF-alpha) in the ...
Lux R, Shi W (July 2004). "Chemotaxis-guided movements in bacteria". Critical Reviews in Oral Biology and Medicine. 15 (4): 207 ... Motile bacteria are attracted or repelled by certain stimuli in behaviours called taxes: these include chemotaxis, phototaxis, ...
H. pylori is able to sense the pH gradient in the mucus and move towards the less acidic region (chemotaxis). This also keeps ... In addition to using chemotaxis to avoid areas of low pH, H. pylori also neutralizes the acid in its environment by producing ... Rust M, Schweinitzer T, Josenhans C (2008). "Helicobacter Flagella, Motility and Chemotaxis". In Yamaoka, Y. (ed.). ...
To move towards a target, the cell uses chemotaxis. It senses extracellular signalling molecules, chemoattractants (e.g. cAMP ... Van Haastert PJM & Devreotes PN (2004). "Chemotaxis: signalling the way forward". Nature Reviews Molecular Cell Biology. 5 (8 ...
... a phenomenon defined as chemotaxis. Chemotaxis has been observed in self-propelled Au-Pt nanorods, which diffuse towards the ... which is known as enzyme chemotaxis. One interesting use of enzyme nanomotor chemotaxis is the separation of active and ... In general, chemotaxis of biological and synthesized self-propelled particles provides a way of directing motion at the ... Hong, Y.; Blackmann, NMK; Kopp, ND.; Sen, A.; Velegol, D. (2007). "Chemotaxis of nonbiological colloidal rods". Physical Review ...
"The Importance of Chemotaxis to the Health of Coral Colonies". Institute for Mathematics and Its Applications. Retrieved 2019- ... "Alexander Kiselev: Reaction enhancement by chemotaxis". National Science Foundation, Mathematical Sciences Institutes. 16 ...
for colony forming unit) chemotaxis (syn. chemotropism) chemotherapy chlamydospore chlamydospore A chlamydospore is the thick- ...
Parallel plate flow chambers are widely used also for drug testing in the cellular chemotaxis assay and for novel targeted drug ... "Drug Testing in Cellular Chemotaxis Assays". Current Protocols in Pharmacology. Unit Number: UNIT 12.11. June, 2008. ...
"A microfluidic Transwell to study chemotaxis". Experimental Cell Research. 342 (2): 159-165. doi:10.1016/j.yexcr.2016.03.010. ...
Zentmyer, G. A. (1961). "Chemotaxis of zoospores for root exudates". Science. 133 (3464): 1595-1596. Bibcode:1961Sci...133.1595 ...
2008). "Helicobacter Flagella, Motility and Chemotaxis". Helicobacter pylori: Molecular Genetics and Cellular Biology (Yamaoka ...
... is called positive if movement is in the direction of a higher concentration of the chemical in question, and ... Chemotaxis is the phenomenon in which bodily cells, bacteria, and other single-cell or multicellular organisms direct their ... In addition, it has been recognized that mechanisms that allow chemotaxis in animals can be subverted during cancer metastasis. ... chemotaxis is critical to early development (e.g. movement of sperm towards the egg during fertilization) and subsequent phases ...
Human neutrophils (white blood cells) are attracted to a chemotactic agent in this time-lapse video. This is one of many videos available for the classroom or broadcast.
... we study a variation of the equations of a chemotaxis kinetic model and investigate it in one dimension. In fact, we use ... Chemotaxis equations. SIAM J. Appl. Math. 62(4), 1222-1250 (2002) (electronic)CrossRefzbMATHMathSciNetGoogle Scholar ... In this paper, we study a variation of the equations of a chemotaxis kinetic model and investigate it in one dimension. In fact ... Chalub F.A.C.C., Rodrigues J.F.: A class of kinetic models for chemotaxis with threshold to prevent overcrowding. Port. Math. ( ...
... Clifford Beall beall.3 at OSU.EDU Mon Nov 7 10:56:45 EST 1994 *Previous message: chemotaxis assays ... I am , a protein biochemist who will shortly set up to do these chemotaxis assays , (Ive never done them before) and any help ... for doing neutrophil chemotaxis assays? The Boyden-chamber seems to be , heavily used but there appear to be other systems that ...
... molecular components involved in chemotaxis, spatiotemporal dynamics of signaling components, and quantitative modeling, as ... chemotaxis of mouse and human neutrophils; and HIV-induced T cell chemotactic response. Chemotaxis: Methods and Protocols, ... Cutting edge and thorough, Chemotaxis: Methods and Protocols, Second Edition is a valuable resource for anyone who is ... 4D Tumorigenesis Model for Quantitating Coalescence, Directed Cell Motility and Chemotaxis, Identifying Unique Cell Behaviors, ...
Eisenbach, M. (2004) Chemotaxis. Imperial College Press, London. Miller, R.L. (1997) Specificity of sperm chemotaxis among ... In some species (for example, herring or the ascidian Ciona) activation of motility precedes chemotaxis. In chemotaxis, cells ... chemotaxis was substantiated as the cause of this accumulation. Sperm chemotaxis was later also demonstrated in mice and ... sperm guidance in the form of sperm chemotaxis has been established in a large variety of species Although sperm chemotaxis is ...
Chemotaxis Cell Migration Gateway Cytometric chemotaxis and cell migration assay Free tool based on ImageJ to analyse ... Chemotaxis assays are experimental tools for evaluation of chemotactic ability of prokaryotic or eukaryotic cells. A wide ... Zicha D.; Dunn G.A.; Brown A.F. (1991). "A new direct-viewing chemotaxis chamber". J Cell Sci. 99: 769-75. PMID 1770004. Leick ... Seymour J. R.; J. R. Ahmed; Marcos S. R (2008). "A microfluidic chemotaxis assay to study microbial behavior in diffusing ...
S. E. Malawista, A. de Boisfleury Chevance, J. van Damme, C. N. Serhan, Tonic inhibition of chemotaxis in human plasma. Proc. ... In fact, the ability of arachidonic acid to enhance chemotaxis depended on EDTA, and pharmacological analysis suggested that ... Oleic acid, however, inhibited chemotaxis in the absence of either EDTA or delipidated albumin; moreover, it inhibited the ... undertook a search for a tonic inhibitor of chemotaxis that might be susceptible to inhibition by this chelator. Analysis of ...
Chemotaxis is achieved by regulating the direction of flagellar rotation. The regulation is carried out by the chemotaxis ... Bacterial chemotaxis, which has been extensively studied for three decades, is the most prominent model system for signal ... Chemotaxis is achieved by regulating the direction of flagellar rotation. The regulation is carried out by the chemotaxis ... Control of bacterial chemotaxis Mol Microbiol. 1996 Jun;20(5):903-10. doi: 10.1111/j.1365-2958.1996.tb02531.x. ...
Chemotaxis System from Sartorius offers a robust walkaway, fully kinetic and image-based solution in 96-well plates. ... Visualize and analyze chemotaxis in real time. Visualize cell migration (top panel). *Time-lapse images of a HT1080 cell ... The new IncuCyte® Chemotaxis System from Sartorius offers a robust walkaway, fully kinetic and image-based solution in 96-well ... 2020, April 01). IncuCyte® Chemotaxis System for Directional Migration Assays. News-Medical. Retrieved on September 24, 2020 ...
Chemotaxis is the movement of small organisms and single cells in response to chemical signals from their environment. The ... During fetal development, chemotaxis also plays a role in the movement of cells as the organism develops; budding nerve cells, ... Research on chemotaxis includes exploration into how small organisms move, when they respond to chemical signals, and what can ... Chemotaxis is movement of small organisms and single cells in response to chemical signals in the surrounding environment. This ...
Dictyostelium discoideum naturally chemotaxes toward chemicals released by bacteria. As part of its developmental life cycle, D ... Assaying chemotaxis of Dictyostelium cells Methods Mol Biol. 2006;346:393-405. doi: 10.1385/1-59745-144-4:393. ... Monitoring chemotaxis toward cAMP and folate allows the determination of signaling events required for sensing a chemical ... As part of its developmental life cycle, D. discoideum chemotaxes towards cAMP. This chapter describes protocols for using ...
The chemotaxis signal transduction pathway allows bacteria to respond to changes in concentration of specific chemicals ( ... The dynamics of protein phosphorylation in bacterial chemotaxis.. Borkovich KA1, Simon MI. ...
... rely heavily upon chemotaxis in order to find areas of food and keep out of areas of harmful substances. One of the im... ... chemotaxis (thing). See all of chemotaxis, there is 1 more in this node. ... E. Coli (and many other bacteria) rely heavily upon chemotaxis in order to find areas of food and keep out of areas of harmful ...
New directions are needed in chemotaxis assays, says Lonza Biosciences. The company is forging ahead by combining microfluidics ... Chemotaxis is a major feature in a number of disease processes-utilized by wound healing, cancer, and immune cells alike. This ... A Closer Look at Chemotaxis. In order to assess the efficiency of this approach as an update to conventional migration assays, ... Chemotaxis is a mechanism that provides directional cellular movement in response to alterations in the chemical composition of ...
Chemotaxis Assay Chemotaxis Assay, Springer Lab. A chemotaxis assays function is to assess whether a factor or molecule of ... Chemotaxis Protocol Links. 12-well Chemotaxis Chamber Protocol 12-well Chemotaxis Chamber Protocol. Preparing the Chamber, ... Chemotaxis Protocol Chemotaxis Protocol by Jeff Hadwiger. Dictyostelium Chemotaxis to Folate: a Simple Assay, from the Hadwiger ... TransWell Chemotaxis Protocol. TransWell Chemotaxis protocol. trans-well chemotaxis method from bioprotocol. The protocol is a ...
... Click on title or image to view video. Chemoattractant receptors in chemotaxis ... G-protein b-subunits in chemotaxis. Confocal image of GFP-tagged Gb-subunits in living amoebae undergoing chemotaxis. The ... PH-domain translocation during chemotaxis. Confocal image of GFP-tagged CRAC in living amoebae undergoing chemotaxis. CRAC-GFP ... Digitized wild-type cell in chemotaxis. Three dimensional direct image reconstruction of a D. discoideum amoebae crawling in a ...
Bacterial chemotaxis, a remarkable behavioral trait which allows bacteria to sense and respond to chemical gradients in the ... Steady gradients, linear or nonlinear, are often a useful model of the bacterial microenvironment to study chemotaxis in the ... Microfluidics for bacterial chemotaxis. Research and Teaching Output of the MIT Community. ... And therefore, studying bacterial chemotaxis is of significant importance to scientists and engineers alike. Microfluidics has ...
Robust perfect adaptation in bacterial chemotaxis through integral feedback control. Tau-Mu Yi, Yun Huang, Melvin I. Simon, ... Robust perfect adaptation in bacterial chemotaxis through integral feedback control. Tau-Mu Yi, Yun Huang, Melvin I. Simon, ... Robust perfect adaptation in bacterial chemotaxis through integral feedback control. Tau-Mu Yi, Yun Huang, Melvin I. Simon, and ... Robust perfect adaptation in bacterial chemotaxis through integral feedback control Message Subject (Your Name) has sent you a ...
Bacterial chemotaxis, conserved biosystem (from KEGG) Bacterial chemotaxis, conserved biosystemChemotaxis is the process by ... Bacterial chemotaxis, organism-specific biosystem (from KEGG) Bacterial chemotaxis, organism-specific biosystemChemotaxis is ... MA; Methyl-accepting chemotaxis-like domains (chemotaxis sensory transducer). pfam00672. Location:210 → 262. HAMP; HAMP domain ... methyl-accepting chemotaxis protein. Locus tag. DVU0183. Gene type. protein coding. RefSeq status. REVIEWED. Organism. ...
... Bernard Girau,1 César Torres-Huitzil,2 Nikolaos ... Similarly, to apply rule R5 (chemotaxis rule), amoebae move to a cell that is randomly selected among the excited free cells of ... We are mostly interested in the decentralized gathering that occurs when amoebae are subject to a chemotaxis process. We now ... N. Fatès, "Gathering agents on a lattice by coupling reaction-diffusion and chemotaxis," Tech. Rep., INRIA Nancy Grand-Est, ...
Here, we scrutinized chemotaxis of single Dictyostelium discoideum cells under conditions of starvation using a variety of ... It turned out that cell-cell contacts as well as cell-substrate contacts form synchronously during chemotaxis of Dictyostelium ... Chemotaxis Is the Subject Area "Chemotaxis" applicable to this article? Yes. No. ...
... Chen Zhang,1,2 Sunyoung Jang,1 Ovid C. Amadi,3,4 Koichi Shimizu ... Chen Zhang, Sunyoung Jang, Ovid C. Amadi, Koichi Shimizu, Richard T. Lee, and Richard N. Mitchell, "A Sensitive Chemotaxis ...
The immune system and nervous system display striking similarities. Fernandis and Ganju discuss yet another example where a protein (Slit) originally identified for its role in modulating axon pathfinding is able to regulate immune cell migration. Slit isoforms expressed in the nervous system interact with members of the Robo receptor family to modify movement stimulated by the secreted attractants netrins and their receptors. In leukocytes, Slit 2 interacting with Robo receptors inhibits movement stimulated by the chemokine receptor (CXCR4). Fernandis and Ganju discuss the therapeutic potential of Slit as an antiviral agent and in the treatment of inflammatory diseases, autoimmune disorders, and cancer. ...
The Gene Ontology (GO) project is a collaborative effort to address the need for consistent descriptions of gene products across databases. You can use this browser to view terms, definitions, and term relationships in a hierarchical display. Links to summary annotated gene data at MGI are provided in Term Detail reports.
In nature, chemotaxis is important for organisms to sense and... ... Chemotaxis is a process in which cells or organisms move in ... Now that the chemotaxis plates and the worms are ready, we can get started on the chemotaxis assay. First, mix equal volumes of ... For example, chemotaxis is required for the movement of sperm toward an egg prior to fertilization. In the lab, chemotaxis is ... Chemotaxis is a process in which cells or organisms move in response to a chemical stimulus. In nature, chemotaxis is important ...
Methyl-accepting chemotaxis proteins (MCPs) are a family of bacterial receptors that mediate chemotaxis to diverse signals, ... Chemotaxis methyl-accepting receptor Tar-related, ligand-binding (IPR003122). Short name: Tar_rcpt_lig-bd ... Transmembrane signaling of chemotaxis receptor tar: insights from molecular dynamics simulation studies.. Biophys. J. 100 2955- ... This entry represents the ligand-binding domain found in a number of methyl-accepting chemotaxis receptors, such as E.coli Tar ...
Sampedro I, Parales RE, Krell T, Hill JE (2015) Pseudomonas chemotaxis. FEMS Microbiol Rev 39:17-46PubMedGoogle Scholar ... Liu X, Parales RE (2009) Bacterial chemotaxis to atrazine and related s-triazines. Appl Environ Microbiol 75:5481-5488CrossRef ... Meng L, Li H, Bao M, Sun P (2017) Metabolic pathway for a new strain Pseudomonas synxantha LSH-7′: from chemotaxis to uptake of ... Particularly, chemotaxis may enable hydrocarbon-utilizing bacteria to actively seek new substrates once they are depleted in a ...
An all-on-chip method enables rapid neutrophil chemotaxis assay directly from a few microliters of blood for both cell ... IMAGE: Illustration of the all-on-chip method for neutrophil chemotaxis analysis using the microfluidic device. Ab-MP: antibody ... All-on-Chip Method for Neutrophil Chemotaxis Analysis Using the Microfluidic Device (IMAGE) view more ... An all-on-chip method for testing neutrophil chemotaxis Those induced by fMLP and COPD patients sputum ...
Chemotaxis can be defined as an innate behavioural response by an organism to a directional stimulus, in which bacteria, and ... Abstract - Chemotaxis can be defined as an innate behavioural response by an organism to a directional stimulus, in which ... dynamic environment computational chemotaxis cooperative foraging period ant colony final result certain chemical food molecule ... abstract chemotaxis adaptive speed ssa collective intelligence multicellular organism global collective behaviour similar ...
  • for doing neutrophil chemotaxis assays? (bio.net)
  • Oleic acid in plasma inhibits neutrophil chemotaxis. (sciencemag.org)
  • I've seen one with examples of neutrophil chemotaxis. (wisegeek.com)
  • Illustration of the all-on-chip method for neutrophil chemotaxis analysis using the microfluidic device. (eurekalert.org)
  • A team of researchers from the University of Manitoba in collaboration with local clinical scientists in Winnipeg, Canada, have developed a new method for rapid neutrophil chemotaxis test directly from a small drop of whole blood using a microfluidic system. (eurekalert.org)
  • In this direction, the present method provides easy-to-use microfluidic devices for efficient on-chip magnetic negative neutrophil isolation from a small drop of whole blood using reagents from a new commercial kit followed by neutrophil chemotaxis assay all on the same device. (eurekalert.org)
  • The method was successfully validated by testing neutrophil chemotaxis to both purified chemoattractant (i.e. fMLP) and clinical samples (sputum from patients with Chronic Obstructive Pulmonary Disease). (eurekalert.org)
  • The traditional cell preparation method significantly limits the efficiency of neutrophil chemotaxis experiment and makes it difficult to run the test in clinical settings. (eurekalert.org)
  • Inhibition of lymphocyte and neutrophil chemotaxis by pertussis toxin. (jimmunol.org)
  • An all-on-chip method for testing neutrophil chemotaxis induced by fMLP and COPD patient's sputum, TECHNOLOGY (2016). (phys.org)
  • Previous studies have reported elevated neutrophil counts in the lung although the determinants of neutrophil chemotaxis in the WG lung are unknown. (ersjournals.com)
  • 11,12) The suppression of neutrophil chemotaxis and phagocytosis has been described. (thefreedictionary.com)
  • The purpose of this project is to determine the effect of tear film of normal horses on neutrophil (PMN) chemotaxis and to compare this PMN chemotaxis to that induced by human tear film. (arvojournals.org)
  • Here, using novel microfluidic approaches, we provide the first description of neutrophil chemotaxis and transcriptomics from whole blood of human term and preterm neonates, as well as young adults. (ovid.com)
  • Ex vivo percent cell migration, neutrophil velocity, and directionality to N-formylmethionyl-leucyl-phenylalanine were measured from whole blood using time-lapse imaging of microfluidic chemotaxis. (ovid.com)
  • In summary, preterm neonates have significant disturbances in neutrophil chemotaxis compared to term neonates and adults, and these differences in phenotype appear at the transcriptional level to target inflammatory pathways in general, rather than in neutrophil migration and chemotaxis. (ovid.com)
  • Chemotaxis, the directed migration of cells, allows neutrophil to seek out the sites of inflammation and infection. (illinois.edu)
  • Neutrophil chemotaxis as well as other type of cell migration are considered as cycles composed of highly orchestrated steps. (illinois.edu)
  • Recently the underlying signaling mechanisms of neutrophil chemotaxis are better understood with the studies in knockout mice and neutrophil-like cell lines: a number of signaling molecules in neutrophil chemotaxis have been identified, and a feedback loop-based model of "frontness" and "backness" pathways has been proposed to explain the establishment of neutrophil polarity and chemotaxis. (illinois.edu)
  • In my first research project, we have identified a signaling pathway, mediated by non-receptor tyrosine kinase Lyn that is essential for localized integrin activation, leading edge attachment, and persistent migration during neutrophil chemotaxis. (illinois.edu)
  • We documented the small GTPase Rap1 as a major downstream effector of Lyn to regulate neutrophil adhesion during chemotaxis. (illinois.edu)
  • Together, these results provide novel mechanistic insights into the poorly understood signaling network that controls leading edge adhesion during neutrophil chemotaxis. (illinois.edu)
  • In my second research project, we have explored the role of mammalian Target of Rapamycin complex 2 (mTORC2) in neutrophil chemotaxis. (illinois.edu)
  • In our studies, we found that mTORC2 is essential for neutrophil chemotaxis. (illinois.edu)
  • Taken together, our findings indicate that mTORC2 is essential for neutrophil chemotaxis by controlling actin polymerization-mediated leading edge protrusion during neutrophil chemotaxis. (illinois.edu)
  • Emerging evidence points to a critical role for the innate immune system, and several studies had documented concurrent impairment in neutrophil chemotaxis with these post-burn inflammatory changes. (biomemsrc.org)
  • While a few studies suggest that a link between neutrophil motility and patient mortality might exist, so far, cumbersome assays have prohibited exploration of the prognostic and diagnostic significance of chemotaxis after burn injury. (biomemsrc.org)
  • Chemotaxis assays are experimental tools for evaluation of chemotactic ability of prokaryotic or eukaryotic cells. (wikipedia.org)
  • Drosophila Larval Chemotaxis Assays Drosophila Larval Chemotaxis Assays. (molecularstation.com)
  • The protocol describes the method used for isolation of monocytes and neutrophils used in both the chemotaxis assay and microbicidal assays. (molecularstation.com)
  • Then, we discuss examples of how chemotaxis assays can be used in C. elegans as a tool to understand learning and memory, olfactory adaptation, and neurological disease such as Alzheimer's disease. (jove.com)
  • Nevertheless, the step response could be reduced to a simple kinetic model that predicted the results of chemotaxis assays. (jneurosci.org)
  • Surprisingly, ablation of the ASE chemosensory neurons, known to be necessary for chemotaxis in chemical gradient assays, eliminated avoidance responses but left approach responses intact. (jneurosci.org)
  • Despite these complexities, the sensorimotor transformation could be described by a simple three-state kinetic model that accurately predicts the behavior of populations of worms in chemotaxis assays. (jneurosci.org)
  • The most important aspects in quality control of chemotaxis assays were described by H. Harris in the 1950s. (wikidoc.org)
  • CRTH2 is a promiscuous receptor and we have used assays of chemotaxis with eosionophils and a CRTH2 transfected cell line, and the Gated-Autofluorescence assay with eosinophils to investigate the ability of a panel of PGD2 metabolites to signal via CRTH2. (regonline.co.uk)
  • This unit describes a number of chemotaxis assays that can be used to identify chemoattractants individually and in large‐scale screenings, to distinguish chemotaxis from chemokinesis, and to analyze cellular behavioral and biochemical responses. (currentprotocols.com)
  • Chemotaxis assays can be used to determine the role of certain odors in many different behaviors including foraging, predator avoidance, and mate attraction. (bio-protocol.org)
  • 2014). Here a detailed protocol for chemotaxis and jumping assays is provided based on the growing body of literature. (bio-protocol.org)
  • In chemotaxis, cells may either sense a temporal gradient of the chemoattractant, comparing the occupancy of its receptors at different time points (as do bacteria), or they may detect a spatial gradient, comparing the occupancy of receptors at different locations along the cell (as do leukocytes). (wikipedia.org)
  • Confocal image of GFP-tagged chemoattractant receptors in living amoebae undergoing chemotaxis. (dictybase.org)
  • In chemotaxis, events at the receptors control autophosphorylat. (nih.gov)
  • Methyl-accepting chemotaxis proteins (MCPs) are a family of bacterial receptors that mediate chemotaxis to diverse signals, responding to changes in the concentration of attractants and repellents in the environment by altering swimming behaviour [ PMID: 16359703 ]. (ebi.ac.uk)
  • This entry represents the ligand-binding domain found in a number of methyl-accepting chemotaxis receptors, such as E.coli Tar (taxis to aspartate and repellents), which is a receptor for the attractant L-aspartate [ PMID: 1660187 , PMID: 27292793 ]. (ebi.ac.uk)
  • A short-term memory required for such comparisons is provided by the adaptation system, which operates through the activity-dependent methylation of chemotaxis receptors. (asm.org)
  • In bacterial chemotaxis, effector stimuli are detected by a set of transmembrane receptors of different specificities ( 1 - 4 ). (asm.org)
  • Together with the histidine kinase CheA and an adaptor protein, CheW, receptors are organized in large sensory complexes that perform most of signal processing in chemotaxis ( 5 - 9 ). (asm.org)
  • In chemotaxis, events at the receptors control autophosphorylation of the CheA histidine kinase, and the phosphohistidine is the substrate for the response regulator CheY, which catalyzes the transfer of the phosphoryl group to a conserved aspartate. (genome.jp)
  • Signal transduction underlying bacterial chemotaxis involves excitatory phosphorylation and feedback control through deamidation and methylation of sensory receptors. (rcsb.org)
  • Chemotaxis, or directional movement toward extracellular chemical gradients, is an important property of cells that is mediated through G-protein-coupled receptors (GPCRs). (rug.nl)
  • The transmembrane signaling mechanism of bacterial chemotaxis receptors is thought to involve changes in receptor conformation and dynamics. (umass.edu)
  • One of these genes, cheD, encodes a protein that is required by the methyltransferase to methylate many of the chemoreceptors (or methyl-accepting chemotaxis proteins), probably by structural modification of the receptors upon binding. (illinois.edu)
  • The bacterial chemotaxis receptors are transmembrane receptors with a simple signalling pathway which has elements relevant to the general understanding of signal recognition and transduction across membranes, how signals are relayed between molecules in a pathway, and how adaptation to a persistent signal is achieved. (proteopedia.org)
  • Bacterial chemotaxis receptors are composed of a ligand-binding domain, a transmembrane domain consisting of two helices TM1 and TM2, and a cytoplasmic domain. (proteopedia.org)
  • All known bacterial chemotaxis receptors have a highly conserved cytoplasmic domain, which unites signals from different ligand domains into a single signalling pathway to flagella motors. (proteopedia.org)
  • Methyl-accepting chemotaxis proteins (MCPs) function as receptors that bind attractants or repellants, usually in the periplasm. (asm.org)
  • In some species (for example, herring or the ascidian Ciona) activation of motility precedes chemotaxis. (wikipedia.org)
  • The chapter includes analyses of random cell motility, directed motility up chemical gradients, cellular responses to uniform chemoattractant exposure, and the utility of fluorescent probes for chemotaxis signaling events. (nih.gov)
  • Steady gradients, linear or nonlinear, are often a useful model of the bacterial microenvironment to study chemotaxis in the limit of slow patch diffusion or fast motility of free swimming bacterial cells. (mit.edu)
  • Interestingly, cell adherence and surface hydrophobicity, biosurfactant production, motility, and chemotaxis processes are bacterial abilities that reduce the distance between the microorganisms and solid substrates, enhancing bioavailability. (springer.com)
  • We particularly focused on a motility response known as chemotaxis and developed a computer model that includes not only intracellular information processing but also motor control. (mit.edu)
  • Two molecular systems drive this process: the motility apparatus and the chemotaxis signal transduction system. (sciencechatforum.com)
  • The proteins constituting the flagellar motor and its switch in archaea have not yet been identified, and the connection between the bacterial-like chemotaxis signal transduction system and the archaeal motility apparatus is unknown. (sciencechatforum.com)
  • Motile bacteria are able to seek out optimal physiological conditions through a behavior known as chemotaxis, where highly conserved signal transduction pathways couple environmental chemical gradients to cellular motility 1 , 2 . (nature.com)
  • We demonstrate that motility and chemotaxis play a crucial role in the collective behaviour - autoaggregation - of E. coli. (uni-marburg.de)
  • CheF, the protein bridging the chemotaxis signal transduction system and the motility apparatus, was recombinantly expressed, purified and subjected to X-ray data collection. (iucr.org)
  • Flagellar motility and chemotaxis by Vibrio fischeri are important behaviors mediating the colonization of its mutualistic host, the Hawaiian bobtail squid. (asm.org)
  • The genome of the squid symbiont Vibrio fischeri (strain ES114) encodes 43 predicted MCPs ( 22 , 23 ), none of which have been studied, despite the importance of chemotaxis and flagellar motility in the symbiotic lifestyle of this organism ( 24 - 28 ). (asm.org)
  • Abstract - Chemotaxis can be defined as an innate behavioural response by an organism to a directional stimulus, in which bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment. (psu.edu)
  • Benov L, Fridovich I (1996) Escherichia coli Exhibits negative chemotaxis in gradients of hydrogen peroxide, hypochlorite, and N-chlorotaurine: products of the respiratory burst of phagocytic cells. (springer.com)
  • Here, we addressed one key aspect of the host-microbe communication by studying chemotaxis of a model commensal bacterium, Escherichia coli , to several compounds present abundantly in the GI tract, namely catecholamines, thyroid hormones, and polyamines. (nature.com)
  • The performance of the device was characterized by comparing chemotaxis of two Escherichia coli species, using aspartic acid as the attractant and nitrate sulfate as the repellent. (rsc.org)
  • Here we demonstrate that the chemotaxis pathway of Escherichia coli does indeed exhibit a universal relation between the response magnitude and adaptation time which does not depend on the type of chemical ligand. (asm.org)
  • Chemotaxis of Escherichia coli. (uni-marburg.de)
  • This means a distinction can be made between chemotaxis and chemokinesis, and researchers are able to better control specific chemical gradients so as to understand cellular behavior under different conditions. (genengnews.com)
  • Bacterial chemotaxis, a remarkable behavioral trait which allows bacteria to sense and respond to chemical gradients in the environment, has implications in a broad range of fields including but not limited to disease pathogenesis, in-situ bioremediation and marine biogeochemistry. (mit.edu)
  • Observed cell distribution along the gradients showed good agreement with predictions from the bacterial transport equation, providing the first quantification of chemotaxis in steady nonlinear gradients. (mit.edu)
  • Bacterial chemotaxis, organism-specific biosystem Chemotaxis is the process by which cells sense chemical gradients in their environment and then move towards more favorable conditions. (nih.gov)
  • Here, we present a comprehensive characterization of the chemotaxis sensorimotor transformation in terms of the behavioral response to concentration steps experienced in steep gradients. (jneurosci.org)
  • We found that the step responses likely to underlie C. elegans chemotaxis in steep gradients are complex, with multiple phases and a nonlinear dependence on the sign and amplitude of the stimulus. (jneurosci.org)
  • Chemotaxis is the process by which cells sense chemical gradients in their environment and then move towards more favorable conditions. (genome.jp)
  • This behavior, conferred by the chemotaxis signaling system, is used to track chemical gradients in liquid. (asm.org)
  • A paper-based invasion assay: assessing chemotaxis of cancer cells in gradients of oxygen. (sigmaaldrich.com)
  • Collective cell chemotaxis, the directed migration of cell groups along gradients of soluble chemical cues, underlies various developmental and pathological processes. (sciencemag.org)
  • Most long-range directed migration in vivo occurs by chemotaxis ( 2 , 4 - 9 ), in which cells follow gradients of soluble chemical cues. (sciencemag.org)
  • Migration to preferred environmental conditions is mediated by a behavior known as chemotaxis ( 2 ), which allows the bacterium to sense gradients of attractants and respond by controlling the directionality of the flagellar motor ( 3 ). (asm.org)
  • The results show that inhibition of either PI3-kinase or PLA2 inhibits chemotaxis in shallow cAMP gradients, whereas both enzymes must be inhibited to prevent chemotaxis in steep cAMP gradients, suggesting that PI3-kinase and PLA2 are two redundant mediators of chemotaxis. (rupress.org)
  • To understand the distinct roles of Aβ on microglial accumulation, we are designinf microfluidic devices to quantify microglial responses to week-long lasting gradients of soluble Aβ and patterns of surface-bound Aβ in microfluidic chemotaxis platforms. (biomemsrc.org)
  • Recntly, we found that human microglia chemotaxis in gradients of soluble Aβ42 could be enhanced by Aβ-induced microglial production of MCP-1. (biomemsrc.org)
  • Directed cell migration can be guided by different types of gradients, for example chemotaxis. (aps.org)
  • Finally, analyzing cells expressing fluorescent fusion proteins is vital to elucidating the location of signaling events during chemotaxis. (nih.gov)
  • Whilst theoretical models have been used to understand aspects of bacterial chemotaxis systems for the past thirty or so years, little work has focused on the importance that spatial localisation of proteins within the cytoplasm of the cell has on the overall functionality of the intracellular network. (videolectures.net)
  • The Che proteins, encoded by genes that cluster in genomes, constitute the chemotaxis signal transduction system. (iucr.org)
  • These proteins demonstrate remarkable similarity to the chemotaxis proteins of enterics and the gliding bacterium Myxococcus xanthus and are thought to be part of a signal transduction system that controls P. (thefreedictionary.com)
  • However, none of the 43 putative methyl-accepting chemotaxis proteins (MCPs) encoded in the V. fischeri genome has been previously characterized. (asm.org)
  • Barkai, Alon, Surette, and Leibler have provided both theoretical and experimental evidence that the precision of adaptation in bacterial chemotaxis is robust to dramatic changes in the levels and kinetic rate constants of the constituent proteins in this signaling network [Alon. (caltech.edu)
  • a research group that previously found that polymorphonuclear leukocytes (PMNs) in plasma treated with the divalent cation chelating agent EDTA showed a prolonged chemotactic response, undertook a search for a tonic inhibitor of chemotaxis that might be susceptible to inhibition by this chelator. (sciencemag.org)
  • A chemotaxis assay's function is to assess whether a factor or molecule of interest has chemotactic activity on a motile cell type. (molecularstation.com)
  • On a chemotaxis model with saturated chemotactic flux. (aimsciences.org)
  • Generally, non-chemotactic mutants lack both positive and negative chemotaxis, and l -methionine is required for both kinds of taxis. (asm.org)
  • Sera from patients with depressed MNL chemotaxis contained a cell-directed chemotactic inhibitor which was heat stable (56°C, 30 min), non-dialyzable and distinct from the sulfadiazine used for topical therapy. (jimmunol.org)
  • To determine the mechanism of chemotaxis, tears were incubated with chemotactic inhibitors prior to placement on microtiter plate. (arvojournals.org)
  • Several methods for detecting or measuring negative chemotaxis are described. (asm.org)
  • Chemoattractants and chemorepellents function to induce either positive or negative chemotaxis respectively. (peprotech.com)
  • negative chemotaxis is movement away from the source. (thefreedictionary.com)
  • The immune system uses cells like neutrophils and macrophages to detect infectious organisms and neutralize them, relying on chemotaxis to sniff out chemicals produced by these cells so it can track them down. (wisegeek.com)
  • Chemotaxis of immunological cells such as leukocytes (neutrophils, monocytes and lymphocytes) and other immune cells. (molecularstation.com)
  • Fibrin is also essential for the chemotaxis of neutrophils and macrophages that play a major role in the healing and the defense against infections. (thefreedictionary.com)
  • The type of inhibition that was observed in these in vitro assay systems was quite similar to that observed in vivo, because PT could depress chemotaxis in vitro as well as the accumulation of radiolabeled lymphocytes and neutrophils within a peripheral site of inflammation in vivo. (jimmunol.org)
  • Chemotaxis of control neutrophils towards BALF from patients with active (p=0.006) and remission WG (p=0.077) and IPF patients (p=0.001) was increased compared with normal controls. (ersjournals.com)
  • Previous investigations (22) showed that LTB4 is the strongest LT triggering inflammation induced by SMU, by having a significant effect on the chemotaxis and activation of neutrophils (4, 23). (thefreedictionary.com)
  • Pharmacological inhibition of mTOR kinase activity and AKT phosphorylation fails to affect actin polymerization and chemotaxis in both human neutrophils and dHL-60 cells. (illinois.edu)
  • The regulation is carried out by the chemotaxis protein, CheY. (nih.gov)
  • The dynamics of protein phosphorylation in bacterial chemotaxis. (nih.gov)
  • DVU0183 methyl-accepting chemotaxis protein [Desulfovibrio vulgaris str. (nih.gov)
  • Its applications in biological studies include quantifying and comparing cellular and subcellular components, estimating DNA and protein concentrations, and analyzing processes like chemotaxis and cell migration. (thefreedictionary.com)
  • AcfB, like another ToxT-dependent VPI protein TcpI, encodes a methyl-accepting chemotaxis protein (MCP) (4). (thefreedictionary.com)
  • An insertion in accA , which encodes the periplasmic binding protein for agrocinopines A+B, abolished chemotaxis while an insertion in accC , which encodes a component of the transport system, and an insertion in accF , which encodes a function required for agrocinopine catabolism, did not affect chemotaxis to this opine. (apsnet.org)
  • The Nia1nit2 mutant with defects in genes encoding the nitrate reductase and regulatory protein NIT2 respectively was found to exhibit normal chemotaxis to nitrite. (mdpi.com)
  • The studies revealed individual elements of the phototropin-dependent signal transduction pathway involved in the blue-light-controlled change in chemotaxis mode of C. reinhardtii during gamete formation: three protein kinases, one operating against signal flux and two that promote signal transduction. (mdpi.com)
  • Even though intracellular signals underlying the regulation of microglia chemotaxis are still not well understood, many attempts focusing on revealing and understanding signaling pathways controlling microglia chemotaxis have been made in recent years. (pubmedcentralcanada.ca)
  • Signaling pathways reported to be involved in the regulation of microglia chemotaxis were depicted in a diagram ( Fig. 2 ). (pubmedcentralcanada.ca)
  • The basic organizational hierarchy of the CSU and the extended hexagonal architecture it forms appear to be universally conserved features of bacterial and archaeal chemotaxis pathways 22 , 23 . (nature.com)
  • methods for studying signal transduction pathways involved in chemotaxis in D. (thefreedictionary.com)
  • Although many chemotaxis pathways downstream of Gβγ have been identified, few Gα effectors are known. (rug.nl)
  • What are the signaling pathways that mediate chemotaxis in pi3k -null cells? (rupress.org)
  • A model of the signal-transduction pathway during sperm chemotaxis of the sea urchin Arbacia punctulata. (wikipedia.org)
  • The chemotaxis signal transduction pathway allows bacteria to respond to changes in concentration of specific chemicals (ligands) by modulating their swimming behavior. (nih.gov)
  • Interestingly, unlike the effect of Mk, Indo showed a predominat effect on mononuclear rather than polymorphonuclear cells, that may be explained by the preferential blockade of the cyclooxygenase pathway that has a lesser effect on the chemotaxis of polymorphonuclear cells. (thefreedictionary.com)
  • Therefore, the chemotaxis signaling pathway is reprogrammed for swarming. (asm.org)
  • Lines of evidence indicate that mTORC2 is essential for the dynamics of actin cytoskeleton: depletion of mTORC2 impairs the organization of actin cytoskeleton in mammalian cells, and knockout of mTORC2 inhibit chemotaxis in D. discoideum through PKB mediated signaling pathway. (illinois.edu)
  • Repeating that process, known as chemotaxis , allows immune cells to find and demolish numerous invaders. (thefreedictionary.com)
  • The significance of chemotaxis in biology and clinical pathology was widely accepted in the 1930s. (wikidoc.org)
  • Considering the significance of chemotaxis in cellular movement during a number of biological processes, including immune response and development, it is of no surprise that a relatively large amount of emphasis has been placed upon research concerning chemotaxis and, more specifically, the Chemokines functioning to direct cellular movement. (peprotech.com)
  • Sperm chemotaxis is a form of sperm guidance, in which sperm cells (spermatozoa) follow a concentration gradient of a chemoattractant secreted from the oocyte and thereby reach the oocyte. (wikipedia.org)
  • In sperm chemotaxis, the oocyte secretes a chemoattractant, which, as it diffuses away, forms a concentration gradient: a high concentration close to the egg, and a gradually lower concentration as the distance from the oocyte increases. (wikipedia.org)
  • In fact, the ability of arachidonic acid to enhance chemotaxis depended on EDTA, and pharmacological analysis suggested that this synergistic effect involved the EDTA-dependent generation of the chemoattractant leukotriene B4 (LTB4) from the added arachidonic acid. (sciencemag.org)
  • The IncuCyte ® live-cell analysis system is used to visualize the directional migration of cells across the surface and toward chemoattractant positioned in the reservoir of the plate and IncuCyte ® Chemotaxis Cell Migration image analysis software is used to quantify this migration. (news-medical.net)
  • Here, we assessed fertilization changes in the presence of a chemoattractant-digesting peptidase and used a microfluidic device coupled with a fertilization assay to determine the effect of sperm chemotaxis on individual male fertilization success in the sea urchin Lytechinus pictus . (biologists.org)
  • 4) Also functional alteration brought about in chemotaxis , phagocytosis and oxidative burst are caused by tobacco smoking. (thefreedictionary.com)
  • Chemotaxis plays a part in the search for food, in fertilization in higher plants and animals, and in phagocytosis. (thefreedictionary.com)
  • The mechanisms responsible for this inhibition were investigated by using the in vitro model systems of polymorphonuclear leukocyte and lymphocyte chemotaxis. (jimmunol.org)
  • As a means of finding food sources during vegetative growth, Dictyostelium discoideum naturally chemotaxes toward chemicals released by bacteria. (nih.gov)
  • As part of its developmental life cycle, D. discoideum chemotaxes towards cAMP. (nih.gov)
  • Chemotaxis toward different cyclic adenosine monophosphate (cAMP) concentrations was tested in Dictyostelium discoideum cell lines with deletion of specific genes together with drugs to inhibit one or all combinations of the second-messenger systems PI3-kinase, phospholipase C (PLC), phospholipase A2 (PLA2), and cytosolic Ca 2+ . (rupress.org)
  • In this study, we investigated the role of several potential second-messenger systems in D. discoideum chemotaxis. (rupress.org)
  • This thesis aims to explore the potential of microfluidic technology in studying bacterial behavior by investigating different aspects of bacterial chemotaxis on a microfluidic platform. (mit.edu)
  • Additional control sites might be involved in bacterial chemotaxis, e.g. lateral control at the receptor level, control at the motor level, or control by metabolites that link central metabolism with chemotaxis. (nih.gov)
  • S. E. Malawista, A. de Boisfleury Chevance, J. van Damme, C. N. Serhan, Tonic inhibition of chemotaxis in human plasma. (sciencemag.org)
  • Although contact inhibition of locomotion and cluster confinement ( 19 , 20 ) are needed for cephalic neural crest directional movement in Xenopus and zebrafish, they are not sufficient, as collective chemotaxis toward SDF1 is essential for long-range directed movement ( 6 ). (sciencemag.org)
  • Clenbuterol, a beta-2-adrenergic agonist that increases icAMP production, demonstrated a dose dependent inhibition of chemotaxis toward equine tears. (arvojournals.org)
  • however, additional inhibition of PLA2 completely blocks chemotaxis, whereas inhibition of PI3-kinase has no effect, suggesting that all chemotaxis in plc -null cells is mediated by PLA2. (rupress.org)
  • The results show that inhibition of PI3K and PLA2 strongly reduces chemotaxis. (rupress.org)
  • Transmembrane signaling of chemotaxis receptor tar: insights from molecular dynamics simulation studies. (ebi.ac.uk)
  • E. Coli (and many other bacteria ) rely heavily upon chemotaxis in order to find areas of food and keep out of areas of harmful substances. (everything2.com)
  • On November 3 , 2006 , Dr. Dennis Bray of University of Cambridge was awarded the Microsoft European Science Award for his work on chemotaxis on E. coli . (wikidoc.org)
  • Along with measurements of drift speeds, we determine how efficiently E. coli use information about the gradient during chemotaxis. (aps.org)
  • Nevertheless, our work shows that, by promoting aggregative behaviour via chemotaxis, AI-2 plays a true signalling function in E. coli. (uni-marburg.de)
  • We further show that this enhancement is due to the interspecies signalling that is mediated by AI-2, which enables E. coli to maintain activity of its quorum sensing system and promotes its chemotaxis-dependent aggregation at lower cell densities. (uni-marburg.de)
  • However, as more diverse bacterial species have been studied, we have learned that bacterial chemotaxis is frequently more complex than the E. coli paradigm ( 10 , 11 ). (asm.org)
  • VcAer2 can serve as a promising alternative to E. coli Aer or PaAer2 for investigating PAS-mediated chemotaxis. (cornell.edu)
  • A. Chertock , K. Fellner , A. Kurganov , A. Lorz and P. Markowich , Sinking, merging and stationary plumes in a coupled chemotaxis-fluid model: a high-resolution numerical approach, Journal of Fluid Mechanics , 694 (2012), 155-190. (aimsciences.org)
  • This observation illustrates a yet-unrecognized function of receptor clustering in bacterial chemotaxis. (asm.org)
  • Several theoretical studies suggested that optimal chemotaxis in a gradient requires a specific adaptation rate that is defined by the gradient steepness and cell swimming velocity ( 31 - 34 ), irrespective of the chemical nature of the ligand or of its receptor specificity. (asm.org)
  • GLUTAMATE RECEPTOR-LIKE channels are essential for chemotaxis and reproduction in mosses. (sigmaaldrich.com)
  • 1.Four-helical-bundle structure of the cytoplasmic domain of a serine chemotaxis receptor. (proteopedia.org)
  • Cells with deletion of the IP 3 receptor have the opposite phenotype: chemotaxis is completely dependent on PI3-kinase and insensitive to PLA2 inhibitors. (rupress.org)
  • In multicellular organisms, chemotaxis is critical to early development (e.g. movement of sperm towards the egg during fertilization ) and subsequent phases of development (e.g. migration of neurons or lymphocytes ) as well as in normal function. (princeton.edu)
  • Sperm chemotaxis was demonstrated in a large number of non-mammalian species, from marine invertebrates to frogs. (wikipedia.org)
  • The molecular mechanism of sperm chemotaxis is still not fully known. (wikipedia.org)
  • Sexual reproduction relies on chemotaxis to allow sperm to migrate toward an egg, following chemoattractants produced by the egg so it can complete fertilization. (wisegeek.com)
  • If they could come up with a method of inserting or producing a chemical which makes the sperm move away from the egg, that could be very non-intrusive, easy way of preventing pregnancy through chemotaxis. (wisegeek.com)
  • For example, chemotaxis is required for the movement of sperm toward an egg prior to fertilization. (jove.com)
  • Sperm chemotaxis, the ability of sperm to navigate towards eggs using chemical signals, has been studied for over a century, but such studies have long assumed that this phenomenon improves individual male fitness without explicit evidence to support this claim. (biologists.org)
  • These results demonstrate that sperm chemotaxis is an important contributor to individual reproductive success. (biologists.org)
  • Work in Pseudomonas aeruginosa , a species that encodes 26 MCPs in strain PAO1, has characterized 9 MCPs that mediate chemotaxis toward ligands such as amino acids, trichloroethylene, and malate ( 15 - 18 ). (asm.org)
  • These results suggest that CpnA plays a role in chemotaxis and adhesion and may do so by interacting with actin filaments. (mdpi.com)
  • Bournaveas N., Calvez V., Gutiérrez S., Perthame B.: Global existence for a kinetic model of chemotaxis via dispersion and Strichartz estimates. (springer.com)
  • This paper presents a qualitative analysis of a model describing the time and space dynamics of a virus which migrates driven by chemotaxis. (aimsciences.org)
  • This provides the first physiologically relevant example of collective behaviour in bacteria being driven by chemotaxis to a self-produced attractant. (uni-marburg.de)
  • Chalub F.A.C.C., Markowich P.A., Perthame B., Schmeiser C.: Kinetic models for chemotaxis and their drift-diffusion limits. (springer.com)
  • Chalub F.A.C.C., Rodrigues J.F.: A class of kinetic models for chemotaxis with threshold to prevent overcrowding. (springer.com)
  • Monitoring chemotaxis toward cAMP and folate allows the determination of signaling events required for sensing a chemical gradient and moving in a directed, persistent manner up the gradient. (nih.gov)
  • Furthermore, the integrated standalone microfluidic gradient generator and cell-docking structure improve the control of cell migration experiment, which enables easier and more accurate chemotaxis analysis. (eurekalert.org)
  • The term chemotaxis is used to describe the movement of organisms or cells in response to the presence of a chemical or chemical gradient, whereby the orientation or movement of the organisms or cells is influenced in a positive or negative manner by the substance exhibiting chemical properties. (peprotech.com)
  • We further found that individual male differences in chemotaxis to a well-defined gradient of attractant correlate with individual male differences in fertilization success. (biologists.org)
  • Chemotaxis is achieved by coupling gradient sensing to basic cell movement. (rupress.org)
  • Two important questions on chemotaxis are (1) What is the compass detecting the cAMP gradient? (rupress.org)
  • In nature, chemotaxis is important for organisms to sense and move toward food sources and move away from stimuli that may be toxic or harmful. (jove.com)
  • There are several well-established techniques, but recent technological advances enable scientists to now view chemotaxis in much finer detail. (genengnews.com)
  • Cells lacking GflB display impaired Rap1/Ras signaling and actin and myosin dynamics, resulting in defective chemotaxis. (rug.nl)
  • The patient's eosinophils had defective chemotaxis, shape changes, and F-actin reorganization against eotaxin, when compared to the controls. (dovepress.com)
  • Rectification of dysregulated CC chemokine signaling for monocyte/macrophage chemotaxis in head and neck squamous cell carcinoma patients by neem leaf glycoprotein maximizes tumor cell cytotoxicity. (thefreedictionary.com)
  • Dictyostelium Chemotaxis to Folate: a Simple Assay, from the Hadwiger Laboratory. (molecularstation.com)
  • Chemotaxis is the phenomenon in which bodily cells, bacteria , and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment. (princeton.edu)
  • This second edition expands on the first edition with new chapters describing methods for studying cell movement, molecular components involved in chemotaxis, spatiotemporal dynamics of signaling components, and quantitative modeling, as well as several updated chapters from the first edition. (springer.com)
  • Chemotaxis: Methods and Protocols, Second Edition also contains microscopy procedures for studying breast cancer cell migration, tumor cell invasion in vivo, and axon guidance. (springer.com)
  • This chapter describes protocols for using Dictyostelium to understand the cell biology behind and the signaling events necessary for eukaryotic amoeboid chemotaxis. (nih.gov)
  • Chemotaxis is the ability of a factor to cause the migration of a cell. (molecularstation.com)
  • Furthermore, the integrated cell-docking feature permits cell pre-alignment in the device before chemotaxis experiment, and therefore it can provide instant chemotaxis test result at the end of the experiment based on the final positions of the cells," says Professor Francis Lin in the Department of Physics and Astronomy at the University of Manitoba and Principal Investigator of this study. (eurekalert.org)
  • Chemotaxis is one of the most basic cell physiological responses. (wikidoc.org)
  • To develop a mathematical model, we make assumptions on individual cell movement, leading to a velocity jump model with chemotaxis. (mdpi.com)
  • Chemotaxis is a complex response of a cell to an external stimulus. (currentprotocols.com)
  • In summary, a 33-day course of maraviroc, an inhibitor of T-cell chemotaxis, appeared to reduce the incidence of acute visceral GVHD without major adverse events. (natap.org)
  • cpnA − cells exhibited defects in three actin-based processes: chemotaxis, cell polarity, and adhesion. (mdpi.com)
  • In this talk, I will first discuss several chemotaxis models includingthe classical Keller-Segel model.Chemotaxis is the phenomenon in which cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals (chemoattractants) in their environment. (gatech.edu)
  • We use neural crest cells, a migratory embryonic stem cell population whose behavior has been likened to malignant invasion, to study collective chemotaxis in vivo. (sciencemag.org)
  • This contractility is polarized during collective cell chemotaxis: It is inhibited at the front but persists at the rear of the cell cluster. (sciencemag.org)
  • We asked whether cells at the group's rear ( Fig. 1A , dotted rectangle) contribute to collective cell chemotaxis. (sciencemag.org)
  • To investigate the mechanism of collective chemotaxis ex vivo and in vivo, we studied Xenopus and zebrafish cranial neural crest cells, an embryonic cell population that undergoes collective cell migration ( 6 , 16 ) in a manner similar to cancer cells ( 17 ), unlike neural crest cells of other species or those in the trunk, where less is known about the collectiveness ( 18 ). (sciencemag.org)
  • Chemotaxis is a pivotal response of many cell types to external spatial cues. (rupress.org)
  • To address this need, we are developing microfluidic devices that are simple to operate and allow for precise and robust measurements of chemotaxis speed and persistence characteristics at single-cell resolution. (biomemsrc.org)
  • While our proposed QBFO takes a new representation of a bacterium, and a new quantum chemotaxis operator and a new quantum elimination-dispersal, which were not considered in these earlier studies. (thefreedictionary.com)
  • In this paper, we study a variation of the equations of a chemotaxis kinetic model and investigate it in one dimension. (springer.com)
  • Bournaveas N., Calvez V.: Global existence for the kinetic chemotaxis model without pointwise memory effects, and including internal variables. (springer.com)
  • Bournaveas N., Calvez V.: Critical mass phenomenon for a chemotaxis kinetic model with spherically symmetric initial data. (springer.com)
  • The new IncuCyte ® Chemotaxis System from Sartorius offers a robust walkaway, fully kinetic and image-based solution in 96-well plates. (news-medical.net)
  • Science Buddies , 12 Jan. 2020, https://www.sciencebuddies.org/science-fair-projects/project-ideas/MicroBio_p028/microbiology/chemotaxis-slime-mold. (sciencebuddies.org)
  • Also, models of chemotaxis in both eukaryotic cells and bacteria will be discussed. (umn.edu)
  • By the use of chambers containing two compartments with an interposed micropore filter, chemotaxis of polymorphonuclear leukocytes (PMN's) in vitro was studied employing various agents that fixed serum complement (C'). Antigen-antibody complexes, zymosan, and aggregated human gamma globulin, in the presence of fresh rabbit, guinea pig, or mouse serum resulted in the migration of PMN's through the micropore filter. (rupress.org)
  • The molecular basis underlying taxis is composed of two systems: chemotaxis signal transduction, which processes the external stimulus, and the flagellum/archaellum, which responds to the chemotaxis output signal. (iucr.org)
  • Cutting edge and thorough, Chemotaxis: Methods and Protocols, Second Edition is a valuable resource for anyone who is interested in the diverse methodologies that are propelling chemotaxis research forward. (springer.com)
  • Chemotaxis protocols and methods. (molecularstation.com)
  • Chemotaxis assay protocols. (molecularstation.com)
  • Chemotaxis is called positive if movement is in the direction of a higher concentration of the chemical in question, and negative if the direction is opposite. (princeton.edu)
  • Chemotaxis is movement of small organisms and single cells in response to chemical signals in the surrounding environment. (wisegeek.com)
  • Chemotaxis is a mechanism that provides directional cellular movement in response to alterations in the chemical composition of the immediate environment. (genengnews.com)
  • Although both can include a number of organic and inorganic substances, the most commonly researched inducers of chemotaxis are chemokines, or cytokines secreted by cells for the purpose of driving cellular movement and activation. (peprotech.com)
  • The movement of insects in response to pheromones may also be regarded as chemotaxis. (thefreedictionary.com)
  • Chemotaxis is a process in which cells or organisms move in response to a chemical stimulus. (jove.com)
  • Female sexual cells of the aquatic fungus Allomyces release the isoprenoid syrenin, a stimulus of chemotaxis of male sexual cells toward female cells. (thefreedictionary.com)
  • The authors thus conclude that oleic acid represents a tonic inhibitor of PMN chemotaxis that could perhaps be manipulated for anti-inflammatory purposes. (sciencemag.org)
  • These studies document that depressed MNL chemotaxis occurs as a consequence of serious thermal trauma, that this defect may be due to a serum inhibitor and that abnormal MNL chemotaxis may contribute to septic morbidity and mortality in severely burned patients. (jimmunol.org)
  • Elevation of intracellular cAMP (icAMP) with rolipram, a selective phosphodiesterase 4 inhibitor, did not significantly affect equine PMN chemotaxis when tested alone. (arvojournals.org)
  • Assessment of the role of chemotaxis and Biofilm formation as requirements for colonization of Roots and seeds of soyabean plants by Bacillus amyloliguefaciens BNM339. (thefreedictionary.com)
  • Bacterial chemotaxis - Bacillus subtilis subsp. (genome.jp)
  • Even in the human pathogen Vibrio cholerae , only 3 of up to 45 putative MCPs, contributing to aerotaxis, amino acid chemotaxis, and chemotaxis toward the chitin-derived sugars N -acetylglucosamine (GlcNAc) and N , N ′-diacetylchitobiose [(GlcNAc) 2 ] have been described ( 19 - 21 ). (asm.org)
  • In the present study, we screened 19 MCPs in V. fischeri ES114 and identified a single gene product that mediates chemotaxis to multiple amino acids. (asm.org)
  • CCR5 plays a role in mediating leukocyte chemotaxis in response to its ligands, which include RANTES, MIP-1a, and MIP-1b. (thefreedictionary.com)
  • In chemotaxis, individual cells, unicellular organisms, and small multicellular organisms respond to chemicals by moving closer or further away from them. (wisegeek.com)
  • Chemicals can interrupt chemotaxis by confusing or disorienting cells, leading them to make mistakes. (wisegeek.com)
  • Chemotaxis of the cells from the upper chamber into the lower chamber can be quantified. (molecularstation.com)
  • Although migration of cells was detected from the early days of the development of microscopy ( Leeuwenhoek ) , erudite description of chemotaxis was first made by T.W. Engelmann (1881) and W.F. Pfeffer (1884) in bacteria and H.S. Jennings (1906) in ciliates . (wikidoc.org)
  • Collectively, this habitat-adapted polymicrobial community residing in the root canal has several biological and pathogenic properties, such as antigenicity, mitogenic activity, chemotaxis , enzymatic histolysis, and activation of host cells. (thefreedictionary.com)
  • The migration of cells in the microwells was monitored and accurately counted to evaluate chemotaxis. (rsc.org)
  • Chemotaxis is usually studied at a transitional phase in development, in which separate cells aggregate together by chemotaxis to cyclic-AMP, en route to forming multicellular structures. (rupress.org)
  • Analysis of the data as a function of time revealed that patients who died generally had depressed chemotaxis immediately postburn and that their cells showed no functional improvement with time. (jimmunol.org)
  • This talk will discuss some recent data obtained using a relatively high-throughput 96 well chemotaxis system, which has allowed us to identify chemoattractants produced by activated mast cells which recruit progenitor mast cells. (regonline.co.uk)
  • RacG-KO cells showed a moderate chemotaxis defect that was stronger in the RacG-V12 and RacG-N17 mutants, in part because of interference with signaling through Rac1. (asm.org)
  • Thus, in neural crest cells, collective chemotaxis works by rear-wheel drive. (sciencemag.org)
  • Depletion of mTORC2, not mTORC1, abolishes fMLP-induced actin polymerization and chemotaxis in dHL-60 cells. (illinois.edu)
  • Unlike vegetative cells and noncompetent pregametes, mature gametes did not show chemotaxis to nitrite. (mdpi.com)
  • These esotactic surfaces have more guidance cues for cells than planar 2D cultures and can disrupt other guidance types like chemotaxis. (aps.org)
  • In our work we propose a family of stable (even at times near blow up) and highly accurate numerical methods, based on interior penalty discontinuous Galerkin schemes (IPDG) for the Keller-Segel chemotaxis model with parabolic-parabolic coupling. (gatech.edu)
  • TTP LabTech offers a high throughput solution for chemotaxis research using the Acumen eX3 microplate cytometer and the iuvo Chemotaxis Assay Plate from BellBrook Labs. (thefreedictionary.com)
  • In multicellular organisms, chemotaxis is critical to development as well as normal function. (wikidoc.org)
  • M. Braukhoff , Global (weak) solution of the chemotaxis-Navier-Stokes equations with non-homogeneous boundary conditions and logistic growth, Annales de l'Institut Henri Poincaré (C) Non Linear Analysis , 34 (2017), 1013-1039. (aimsciences.org)
  • H. J. Choe and B. Lkhagvasuren , Global existence result for chemotaxis Navier-Stokes equations in the critical Besov spaces, Journal of Mathematical Analysis and Applications , 446 (2017), 1415-1426. (aimsciences.org)
  • In addition, it has been recognized that mechanisms that allow chemotaxis in animals can be subverted during cancer metastasis . (princeton.edu)
  • Thus CheY phosphorylation appears to be involved in controlling both the excitation and adaptation mechanisms of bacterial chemotaxis. (nih.gov)
  • Chemotaxis experiments in C. elegans have near-limitless possibilities for learning more about the cellular and genetic mechanisms of many biological processes, and may lead to a greater understanding of human biology, development, and disease. (jove.com)