Adenylate Cyclase Toxin
Virulence Factors, Bordetella
Pituitary Adenylate Cyclase-Activating Polypeptide
Molecular Sequence Data
Receptors, Adrenergic, beta
Adenosine Diphosphate Ribose
Probing the function of Bordetella bronchiseptica adenylate cyclase toxin by manipulating host immunity. (1/644)We have examined the role of adenylate cyclase-hemolysin (CyaA) by constructing an in-frame deletion in the Bordetella bronchiseptica cyaA structural gene and comparing wild-type and cyaA deletion strains in natural host infection models. Both the wild-type strain RB50 and its adenylate cyclase toxin deletion (DeltacyaA) derivative efficiently establish persistent infections in rabbits, rats, and mice following low-dose inoculation. In contrast, an inoculation protocol that seeds the lower respiratory tract revealed significant differences in bacterial numbers and in polymorphonuclear neutrophil recruitment in the lungs from days 5 to 12 postinoculation. We next explored the effects of disarming specific aspects of the immune system on the relative phenotypes of wild-type and DeltacyaA bacteria. SCID, SCID-beige, or RAG-1(-/-) mice succumbed to lethal systemic infection following high- or low-dose intranasal inoculation with the wild-type strain but not the DeltacyaA mutant. Mice rendered neutropenic by treatment with cyclophosphamide or by knockout mutation in the granulocyte colony-stimulating factor locus were highly susceptible to lethal infection by either wild-type or DeltacyaA strains. These results reveal the significant role played by neutrophils early in B. bronchiseptica infection and by acquired immunity at later time points and suggest that phagocytic cells are a primary in vivo target of the Bordetella adenylate cyclase toxin. (+info)
Distinct roles for Galphai2, Galphai3, and Gbeta gamma in modulation offorskolin- or Gs-mediated cAMP accumulation and calcium mobilization by dopamine D2S receptors. (2/644)Previous studies have shown that a single G protein-coupled receptor can regulate different effector systems by signaling through multiple subtypes of heterotrimeric G proteins. In LD2S fibroblast cells, the dopamine D2S receptor couples to pertussis toxin (PTX)-sensitive Gi/Go proteins to inhibit forskolin- or prostaglandin E1-stimulated cAMP production and to stimulate calcium mobilization. To analyze the role of distinct Galphai/o protein subtypes, LD2S cells were stably transfected with a series of PTX-insensitive Galphai/o protein Cys --> Ser point mutants and assayed for D2S receptor signaling after PTX treatment. The level of expression of the transfected Galpha mutant subunits was similar to the endogenous level of the most abundant Galphai/o proteins (Galphao, Galphai3). D2S receptor-mediated inhibition of forskolin-stimulated cAMP production was retained only in clones expressing mutant Galphai2. In contrast, the D2S receptor utilized Galphai3 to inhibit PGE1-induced (Gs-coupled) enhancement of cAMP production. Following stable or transient transfection, no single or pair set of mutant Galphai/o subtypes rescued the D2S-mediated calcium response following PTX pretreatment. On the other hand, in LD2S cells stably transfected with GRK-CT, a receptor kinase fragment that specifically antagonizes Gbeta gamma subunit activity, D2S receptor-mediated calcium mobilization was blocked. The observed specificity of Galphai2 and Galphai3 for different states of adenylyl cyclase activation suggests a higher level of specificity for interaction of Galphai subunits with forskolin- versus Gs-activated states of adenylyl cyclase than has been previously appreciated. (+info)
GABA(B) receptor-mediated stimulation of adenylyl cyclase activity in membranes of rat olfactory bulb. (3/644)Previous studies have shown that GABA(B) receptors facilitate cyclic AMP formation in brain slices likely through an indirect mechanism involving intracellular second messengers. In the present study, we have investigated whether a positive coupling of GABA(B) receptors to adenylyl cyclase could be detected in a cell-free preparation of rat olfactory bulb, a brain region where other Gi/Go-coupled neurotransmitter receptors have been found to stimulate the cyclase activity. The GABA(B) receptor agonist (-)-baclofen significantly increased basal adenylyl cyclase activity in membranes of the granule cell and external plexiform layers, but not in the olfactory nerve-glomerular layer. The adenylyl cyclase stimulation was therefore examined in granule cell layer membranes. The (-)-baclofen stimulation (pD2=4.53) was mimicked by 3-aminopropylphosphinic acid (pD2=4.60) and GABA (pD2=3.56), but not by (+)-baclofen, 3-aminopropylphosphonic acid, muscimol and isoguvacine. The stimulatory effect was counteracted by the GABA(B) receptor antagonists CGP 35348 (pA2=4.31), CGP 55845 A (pA2=7.0) and 2-hydroxysaclofen (pKi=4.22). Phaclofen (1 mM) was inactive. The (-)-baclofen stimulation was not affected by quinacrine, indomethacin, nordihydroguaiaretic acid and staurosporine, but was completely prevented by pertussis toxin and significantly reduced by the alpha subunit of transducin, a betagamma scavenger. The betagamma subunits of transducin stimulated the cyclase activity and this effect was not additive with that produced by (-)-baclofen. In the external plexiform and granule cell layers, but not in the olfactory nerve-glomerular layer, (-)-baclofen enhanced the adenylyl cyclase stimulation elicited by the neuropeptide pituitary adenylate cyclase activating polypeptide (PACAP) 38. Conversely, the adenylyl cyclase activity stimulated by either forskolin or Ca2+/calmodulin-(Ca2+/CaM) was inhibited by (-)-baclofen in all the olfactory bulb layers examined. These data demonstrate that in specific layers of rat olfactory bulb activation of GABA(B) receptors enhances basal and neurotransmitter-stimulated adenylyl cyclase activities by a mechanism involving betagamma subunits of Gi/Go. This positive coupling is associated with a widespread inhibitory effect on forskolin- and Ca2+/CaM-stimulated cyclic AMP formation. (+info)
Signalling by CXC-chemokine receptors 1 and 2 expressed in CHO cells: a comparison of calcium mobilization, inhibition of adenylyl cyclase and stimulation of GTPgammaS binding induced by IL-8 and GROalpha. (4/644)The effect of interleukin-8 (IL-8) and growth-related oncogene alpha (GROalpha) on [35S]-guanosine 5'-O-(3-thiotriphosphate) ([35S]GTPgammaS) binding, forskolin-stimulated cyclic AMP accumulation and cytosolic calcium concentration were determined in recombinant CHO cells expressing HA-tagged CXC-chemokine receptors 1 and 2 (CXCR1 and CXCR2). Radioligand binding assays confirmed that the binding profiles of the recombinant receptors were similar to those of the native proteins. IL-8 displaced [125I]-IL-8 binding to CXCR1 and CXCR2 with pKi values of 8.89+/-0.05 and 9.27+/-0.03, respectively. GROalpha, a selective CXCR2 ligand, had a pKi value of 9.66+/-0.39 at CXCR2 but a pKi>8 at CXCR1. Calcium mobilization experiments were also consistent with previous reports on native receptors. Activation of both receptors resulted in stimulation of [35S]GTPgammaS binding and inhibition of adenylyl cyclase. A comparison of the functional data at CXCRI showed that a similar potency order (IL-8> >GROalpha) was obtained in all three assays. However, at CXCR2 whilst the potency orders for calcium mobilization and inhibition of adenylyl cyclase were similar (IL-8 > or = GROalpha), the order was reversed for stimulation of [35S]GTPgammaS binding (GROalpha > IL-8). All of the functional responses at both receptors were inhibited by pertussis toxin (PTX), suggesting coupling to a Gi/Go protein. However, the calcium mobilization induced by IL-8 at CXCR1 was not fully inhibited by PTX, suggesting an interaction with a G-protein of the Gq family. Our results with pertussis toxin also suggested that, in the [35S]GTPgammaS binding assay, CXCR1 displays some constitutive activity. Thus, we have characterized the binding and several functional responses at HA-tagged CXCRs 1 and 2 and have shown that their pharmacology agrees well with that of the native receptors. We also have preliminary evidence that CXCR1 displays constitutive activity in our cell line and that CXCR2 may traffic between different PTX sensitive G-proteins. (+info)
Cell-specific coupling of PGE2 to different transduction pathways in arginine vasopressin- and glucagon-sensitive segments of the rat renal tubule. (5/644)1. The aim of the present study was to investigate the transduction pathways elicited by prostaglandin E2 (PGE2) to inhibit hormone-stimulated adenosine 3':5'-cyclic monophosphate (cyclic AMP) accumulation in the outer medullary collecting duct (OMCD) and medullary thick ascending limb (MTAL) microdissected from the rat nephron. 2. In the OMCD, 0.3 microM PGE2 and low concentrations of Ca2+ ionophores (10 nM ionomycin or 50 nM A23187) inhibited by about 50% a same pool of arginine vasopressin (AVP)-stimulated cyclic AMP content through a same process insensitive to Bordetella pertussis toxin (PTX). 3. Sulprostone, an agonist of the EP1/EP3 subtypes of the PGE2 receptor, decreased AVP-dependent cyclic AMP accumulation in OMCD and MTAL samples. The concentration eliciting half-maximal inhibition was of about 50 nM in OMCD and 0.1 nM in MTAL. 4. In MTAL, 1 nM sulprostone and PGE2 inhibited by about 90% a same pool of AVP-dependent cyclic AMP content through a PTX-sensitive, Ca2+ -independent pathway. 5. In the OMCD, PGE2 decreased by about 50% glucagon-dependent cyclic AMP synthesis by a process sensitive to PTX and Ca2+ -independent. Sulprostone 1 nM induced the same level of inhibition. 6. These results demonstrate that PGE2 decrease hormone-dependent cyclic AMP accumulation through a G(alpha)i-mediated inhibition of adenylyl cyclase activity in MTAL cells and glucagon-sensitive cells of the OMCD or through a PTX-insensitive increase of intracellular Ca2+ concentration in AVP-sensitive cells of the OMCD. (+info)
The conserved lysine 860 in the additional fatty-acylation site of Bordetella pertussis adenylate cyclase is crucial for toxin function independently of its acylation status. (6/644)The Bordetella pertussis RTX (repeat in toxin family protein) adenylate cyclase toxin-hemolysin (ACT) acquires biological activity upon a single amide-linked palmitoylation of the epsilon-amino group of lysine 983 (Lys983) by the accessory fatty-acyltransferase CyaC. However, an additional conserved RTX acylation site can be identified in ACT at lysine 860 (Lys860), and this residue becomes palmitoylated when recombinant ACT (r-Ec-ACT) is produced together with CyaC in Escherichia coli K12. We have eliminated this additional acylation site by replacing Lys860 of ACT with arginine, leucine, and cysteine residues. Two-dimensional gel electrophoresis and microcapillary high performance liquid chromatography/tandem mass spectrometric analyses of mutant proteins confirmed that the two sites are acylated independently in vivo and that mutations of Lys860 did not affect the quantitative acylation of Lys983 by palmitoyl (C16:0) and palmitoleil (cis Delta9 C16:1) fatty-acyl groups. Nevertheless, even the most conservative substitution of lysine 860 by an arginine residue caused a 10-fold decrease of toxin activity. This resulted from a 5-fold reduction of cell association capacity and a further 2-fold reduction in cell penetration efficiency of the membrane-bound K860R toxin. These results suggest that lysine 860 plays by itself a crucial structural role in membrane insertion and translocation of the toxin, independently of its acylation status. (+info)
Therapy of murine tumors with recombinant Bordetella pertussis adenylate cyclase carrying a cytotoxic T cell epitope. (7/644)Bordetella pertussis secretes an invasive adenylate cyclase toxin, CyaA, that is able to deliver its N-terminal catalytic domain into the cytosol of eukaryotic target cells directly through the cytoplasmic membrane. We have shown previously that recombinant CyaA can be used to deliver viral CD8+ T cell epitopes to the MHC-class I presentation pathway to trigger specific CTL responses in vivo. In the present study, we show that mice immunized with a detoxified but still invasive CyaA carrying a CD8+ T cell epitope of OVA developed strong epitope-specific CTL responses, which kill tumor cells expressing this Ag. Treating mice with this recombinant molecule after the graft of melanoma cells expressing OVA induced a strong survival advantage compared with control animals. To our knowledge, this study represents the first demonstration that a nonreplicative and nontoxic vector carrying a single CTL epitope can stimulate efficient protective and therapeutic antitumor immunity. (+info)
Activation of adenylate cyclase by human recombinant sst5 receptors expressed in CHO-K1 cells and involvement of Galphas proteins. (8/644)1. The coupling of the human somatostatin sst5 receptor recombinantly expressed in Chinese hamster ovary (CHO-K1) cells to adenylate cyclase was investigated using receptor selective ligands. 2. Forskolin (10 microM)-stimulated adenosine 3': 5'-cyclic monophosphate (cyclic AMP) accumulation was inhibited by somatostatin-14 and a number of receptor-selective agonists with a rank order of agonist potency typical of the sst5 receptor. L-362,855 and BIM-23056 behaved as full agonists. At higher somatostatin-14 concentrations there was sub-maximal inhibition resulting in a bell-shaped concentration-effect relationship. Pertussis toxin (PTx; 100 ng ml(-1), 18 h) pre-treatment abolished agonist-mediated inhibition of cyclic AMP accumulation and markedly enhanced stimulation of cyclic AMP at higher agonist concentrations. 3. The concentration of prostaglandin E2 (PGE2) in the incubation media was raised 14 fold by 1 microM somatostatin-14 but was insufficient to stimulate adenylate cyclase activity via endogenous prostanoid receptors. 4. Pre-treatment with cholera toxin (ChTx; 20 microg ml(-1), 18 h) markedly inhibited sst5 receptor-mediated increases in cyclic AMP formation in intact cells. Somatostatin-14-stimulated cyclic AMP accumulation was also observed in sst5 receptor containing CHO-K1 membranes and was inhibited by the synthetic peptide Galphasacetyl-354-372-amide (100 microM) by 65.9+/-3.5%, implicating a Galphas protein involvement in this response. 5. Activation of Galphas proteins by somatostatin-14 could be demonstrated with [35S]-guanosine 5'-[gamma-thio]triphosphate ([35S]-GTPgammaS) binding and subsequent immunoprecipitation of 35S labelled Galphas proteins with anti-Galphas serum. 6. These data show that the sst5 receptor is very efficiently coupled in a negative manner to adenylate cyclase. However, at higher agonist concentrations the receptor can also mediate activation of adenylate cyclase by a mechanism apparently involving Galphas protein activation. (+info)
Adenylate cyclase toxin (ACT) is a bacterial toxin produced by certain strains of the bacterium Bordetella pertussis, which is the causative agent of whooping cough. The toxin is a member of the adenylate cyclase toxin family, which is a group of toxins that share a common mechanism of action. ACT works by binding to and activating adenylate cyclase, an enzyme that catalyzes the conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP). This leads to an increase in intracellular cAMP levels, which in turn causes a number of cellular responses, including the activation of protein kinase A (PKA) and the inhibition of phosphodiesterase (PDE). The effects of ACT on the host cell can be detrimental, leading to cell death, inflammation, and disruption of normal cellular processes. In the case of B. pertussis infection, ACT is thought to play a role in the pathogenesis of whooping cough by contributing to the inflammation and damage to the respiratory tract. ACT is also produced by other bacteria, including Bordetella bronchiseptica and Bordetella parapertussis, and has been shown to have a number of other effects on host cells, including the induction of apoptosis and the modulation of immune responses.
Bordetella pertussis is a Gram-negative, aerobic, coccobacillus bacteria that is the causative agent of whooping cough, also known as pertussis. It is a highly contagious respiratory infection that primarily affects young children, but can also affect adults and infants who have not been vaccinated. The bacteria produces a number of virulence factors, including a toxin that causes severe coughing fits, which can lead to difficulty breathing and even death in severe cases. Pertussis is typically spread through the air when an infected person coughs or sneezes, and can also be transmitted through contaminated surfaces or objects. Treatment for pertussis typically involves antibiotics to help the body fight off the infection, as well as supportive care to manage symptoms such as coughing fits and difficulty breathing. Vaccination is the most effective way to prevent pertussis.
Adenylate cyclase is an enzyme that catalyzes the conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP), a second messenger molecule that plays a crucial role in many cellular signaling pathways. In the medical field, adenylate cyclase is often studied in the context of its role in regulating various physiological processes, including heart rate, blood pressure, and glucose metabolism. It is also involved in the regulation of hormone signaling, particularly in the endocrine system, where hormones such as adrenaline and thyroid hormones bind to specific receptors on the cell surface and activate adenylate cyclase, leading to the production of cAMP and the activation of downstream signaling pathways. Abnormalities in adenylate cyclase activity have been implicated in a number of diseases, including diabetes, hypertension, and certain forms of heart disease. As such, understanding the regulation and function of adenylate cyclase is an important area of research in the medical field.
Bordetella bronchiseptica is a Gram-negative, aerobic, non-spore-forming bacterium that belongs to the family Pasteurellaceae. It is a common pathogen that causes respiratory tract infections in a wide range of animals, including dogs, cats, birds, rodents, and livestock. In dogs, B. bronchiseptica is a significant cause of kennel cough, a highly contagious respiratory disease that is characterized by a persistent cough, difficulty breathing, and sometimes fever. The bacteria can also cause other respiratory infections, such as tracheobronchitis and pneumonia. In cats, B. bronchiseptica is less common but can cause similar respiratory symptoms. It can also cause conjunctivitis, a condition that affects the eyes. B. bronchiseptica is typically spread through the air when an infected animal coughs or sneezes. It can also be transmitted through contaminated surfaces or objects. Treatment for B. bronchiseptica infections typically involves antibiotics and supportive care to manage symptoms. Vaccines are available to prevent the disease in dogs and cats.
Bordetella infections are caused by bacteria of the genus Bordetella, which includes Bordetella pertussis (whooping cough), Bordetella parapertussis, and Bordetella bronchiseptica. These bacteria can cause a range of respiratory infections in humans and animals, including whooping cough, bronchitis, and pneumonia. Bordetella pertussis is the most well-known of these bacteria and is responsible for whooping cough, a highly contagious respiratory infection that primarily affects children. Whooping cough is characterized by a severe cough that can last for several weeks, often followed by a whooping sound when the person inhales. In severe cases, whooping cough can be life-threatening, particularly in young children. Bordetella parapertussis is a less common cause of whooping cough, but it can cause similar symptoms to Bordetella pertussis. Bordetella bronchiseptica is a common cause of respiratory infections in animals, but it can also cause infections in humans, particularly in immunocompromised individuals. Treatment for Bordetella infections typically involves antibiotics to kill the bacteria. In the case of whooping cough, vaccination is also an important preventive measure.
Hemolysis is the breakdown of red blood cells (RBCs) in the bloodstream. This process can occur due to various factors, including mechanical stress, exposure to certain medications or toxins, infections, or inherited genetic disorders. When RBCs are damaged or destroyed, their contents, including hemoglobin, are released into the bloodstream. Hemoglobin is a protein that carries oxygen from the lungs to the body's tissues and carbon dioxide from the tissues back to the lungs. When hemoglobin is released into the bloodstream, it can cause the blood to appear dark brown or black, a condition known as hemoglobinuria. Hemolysis can lead to a variety of symptoms, including jaundice (yellowing of the skin and eyes), fatigue, shortness of breath, abdominal pain, and dark urine. In severe cases, hemolysis can cause life-threatening complications, such as kidney failure or shock. Treatment for hemolysis depends on the underlying cause. In some cases, treatment may involve medications to slow down the breakdown of RBCs or to remove excess hemoglobin from the bloodstream. In other cases, treatment may involve blood transfusions or other supportive therapies to manage symptoms and prevent complications.
Whooping cough, also known as pertussis, is a highly contagious respiratory infection caused by the bacterium Bordetella pertussis. It is characterized by a series of coughing fits that can last for several weeks, often followed by a whooping sound when the person inhales after a coughing fit. The symptoms of whooping cough typically begin with a runny nose, sneezing, and mild cough. As the infection progresses, the coughing fits become more severe and may be followed by a high-pitched "whoop" sound when the person inhales. The coughing fits can be so severe that they can cause vomiting and loss of consciousness in severe cases. Whooping cough is most common in children, but it can also affect adults. It is highly contagious and can be spread through the air when an infected person coughs or sneezes. The best way to prevent whooping cough is through vaccination, which is recommended for all children and adults.
Cyclic AMP (cAMP) is a signaling molecule that plays a crucial role in many cellular processes, including metabolism, gene expression, and cell proliferation. It is synthesized from adenosine triphosphate (ATP) by the enzyme adenylyl cyclase, and its levels are regulated by various hormones and neurotransmitters. In the medical field, cAMP is often studied in the context of its role in regulating cellular signaling pathways. For example, cAMP is involved in the regulation of the immune system, where it helps to activate immune cells and promote inflammation. It is also involved in the regulation of the cardiovascular system, where it helps to regulate heart rate and blood pressure. In addition, cAMP is often used as a tool in research to study cellular signaling pathways. For example, it is commonly used to activate or inhibit specific signaling pathways in cells, allowing researchers to study the effects of these pathways on cellular function.
Bordetella is a genus of gram-negative bacteria that are commonly found in the respiratory tract of humans and animals. There are several species of Bordetella, including Bordetella pertussis, Bordetella parapertussis, and Bordetella bronchiseptica. Bordetella pertussis is the causative agent of whooping cough, a highly contagious respiratory infection that primarily affects children. The bacteria produce a toxin that causes severe coughing fits, which can lead to difficulty breathing and even death in severe cases. Bordetella parapertussis is a less common cause of whooping cough, but it can cause similar symptoms to B. pertussis. Bordetella bronchiseptica is a common cause of respiratory infections in animals, but it can also cause respiratory infections in humans, particularly in immunocompromised individuals. In the medical field, Bordetella species are commonly identified using bacterial culture and molecular techniques such as polymerase chain reaction (PCR). Treatment for Bordetella infections typically involves antibiotics, although there is currently no vaccine available for whooping cough caused by B. pertussis.
CD11b is a type of protein found on the surface of certain immune cells, such as neutrophils and monocytes. It is a member of the integrin family of proteins, which are involved in cell adhesion and signaling. CD11b is also known as the alpha chain of the integrin receptor Mac-1 (Macrophage-1 antigen). Antigens, CD11b are molecules that bind to CD11b on the surface of immune cells. These antigens can be foreign substances, such as bacteria or viruses, or they can be self-molecules that have been altered in some way. When CD11b binds to an antigen, it triggers a series of signaling events that activate the immune cell and cause it to respond to the presence of the antigen. This response can include the production of inflammatory molecules, the recruitment of other immune cells to the site of the antigen, and the destruction of the antigen. CD11b and its antigens play an important role in the immune response and are the subject of ongoing research in the field of immunology.
Pertussis toxin is a protein toxin produced by Bordetella pertussis, the bacterium responsible for whooping cough. It is one of the major virulence factors of B. pertussis and plays a key role in the pathogenesis of the disease. Pertussis toxin is a complex molecule composed of two subunits: the A subunit, which is responsible for its toxic effects, and the B subunit, which is responsible for its binding to host cells. The A subunit of pertussis toxin ADP-ribosylates a specific host cell protein, called the G protein, which is involved in signal transduction pathways. This ADP-ribosylation leads to the inhibition of the G protein, which in turn disrupts normal cellular signaling and causes a variety of toxic effects, including inflammation, cell death, and disruption of the respiratory system. Pertussis toxin is a major contributor to the severity of whooping cough, and it is the target of several vaccines used to prevent the disease. In addition to its role in whooping cough, pertussis toxin has also been studied for its potential use as a therapeutic agent in the treatment of other diseases, such as cancer and autoimmune disorders.
Hemolysin proteins are a group of toxins produced by certain bacteria that can cause damage to red blood cells (erythrocytes). These proteins are capable of disrupting the integrity of the cell membrane, leading to the release of hemoglobin, which can cause hemoglobinemia (an excess of hemoglobin in the blood) and hemoglobinuria (the presence of hemoglobin in the urine). Hemolysins can be classified into several types based on their mechanism of action and the target cells they affect. Some hemolysins, such as streptolysin O and pneumolysin, are pore-forming toxins that create holes in the cell membrane, leading to cell lysis and death. Other hemolysins, such as alpha-hemolysin, act by disrupting the cell membrane's lipid bilayer, leading to cell lysis. Hemolysins are produced by a variety of bacterial species, including Streptococcus pyogenes, Staphylococcus aureus, and Clostridium perfringens. Infections caused by these bacteria can lead to a range of symptoms, including fever, chills, nausea, vomiting, and abdominal pain. In severe cases, hemolysin production can lead to sepsis, a life-threatening condition characterized by widespread inflammation and organ dysfunction.
CD18 is a cluster of differentiation antigens that are expressed on the surface of many immune cells, including neutrophils, monocytes, and macrophages. CD18 is a component of the integrin family of cell adhesion molecules, which play a critical role in the recruitment and activation of immune cells at sites of inflammation or infection. Antigens, CD18 are proteins that are recognized by the immune system as foreign or non-self. They are often used as markers to identify and study immune cells, and they can also be targeted by therapeutic agents to modulate immune responses. In the context of infectious diseases, CD18 antigens may be recognized by the immune system as part of the pathogen, leading to the activation and recruitment of immune cells to eliminate the infection.
Bacterial toxins are harmful substances produced by certain types of bacteria that can cause damage to living cells and tissues. These toxins can be excreted by the bacteria or released into the surrounding environment, where they can be absorbed by the body and cause illness. Bacterial toxins can be classified into two main categories: exotoxins and endotoxins. Exotoxins are proteins that are secreted by the bacteria and can be directly toxic to cells. Endotoxins, on the other hand, are lipopolysaccharides that are found in the cell wall of gram-negative bacteria and are released when the bacteria die or are disrupted. Bacterial toxins can cause a wide range of illnesses, including food poisoning, botulism, tetanus, and diphtheria. The severity of the illness caused by a bacterial toxin depends on the type of toxin, the amount of toxin that is ingested or absorbed, and the overall health of the individual. Treatment for bacterial toxin poisoning typically involves supportive care, such as fluid replacement and medications to manage symptoms. In some cases, antibiotics may be used to treat the underlying bacterial infection that produced the toxin. Vaccines are also available for some bacterial toxins, such as tetanus and diphtheria.
Cholera toxin is a protein complex produced by the bacterium Vibrio cholerae, which is the causative agent of cholera. The toxin is composed of two subunits: A1 and A2. The A1 subunit binds to the GM1 ganglioside receptor on the surface of host cells, while the A2 subunit is responsible for the toxic effects of the toxin. When cholera toxin enters the body, it binds to the GM1 ganglioside receptor on the surface of cells in the small intestine. This binding triggers the release of intracellular calcium ions, which leads to the activation of a signaling pathway that results in the secretion of large amounts of water and electrolytes into the intestinal lumen. This excessive secretion of fluids leads to severe diarrhea, dehydration, and electrolyte imbalances, which can be life-threatening if left untreated. Cholera toxin is a potent virulence factor that plays a critical role in the pathogenesis of cholera. It is also used as a tool in research to study the mechanisms of cellular signaling and to develop vaccines against cholera.
Adenylate kinase (AK) is an enzyme that plays a crucial role in cellular metabolism by catalyzing the reversible transfer of a high-energy phosphate group from one adenosine triphosphate (ATP) molecule to another, generating adenosine diphosphate (ADP) and inorganic phosphate (Pi). This reaction helps to maintain the balance of ATP and ADP levels within cells, which is essential for energy metabolism and other cellular processes. In the medical field, AK is involved in various physiological and pathological processes, including muscle contraction, glucose metabolism, and cell proliferation. AK is also a potential therapeutic target for various diseases, such as cancer, cardiovascular disease, and neurodegenerative disorders. Therefore, understanding the regulation and function of AK is important for developing new treatments and therapies for these diseases.
Guanylate cyclase is an enzyme that plays a crucial role in the regulation of various physiological processes in the body, including blood pressure, smooth muscle contraction, and immune function. It is a membrane-bound protein that catalyzes the conversion of guanosine triphosphate (GTP) to cyclic guanosine monophosphate (cGMP), a second messenger molecule that regulates the activity of various proteins in the cell. In the cardiovascular system, guanylate cyclase is activated by nitric oxide (NO), a signaling molecule that is released by endothelial cells in response to various stimuli, such as shear stress or the presence of certain hormones. Activation of guanylate cyclase by NO leads to an increase in cGMP levels, which in turn causes relaxation of smooth muscle cells in blood vessels, leading to vasodilation and a decrease in blood pressure. Guanylate cyclase is also involved in the regulation of immune function, as it is activated by various immune cells and cytokines. Activation of guanylate cyclase by immune cells leads to the production of cGMP, which regulates the activity of immune cells and helps to maintain immune homeostasis. In addition, guanylate cyclase is involved in the regulation of various other physiological processes, such as neurotransmission, vision, and hearing. It is a key enzyme in the regulation of these processes and plays a crucial role in maintaining normal physiological function.
Guanylyl Imidodiphosphate (GMP-ribose-5'-triphosphate, or GTP) is a molecule that plays a crucial role in various cellular processes, including signal transduction, protein synthesis, and cell division. It is a type of nucleotide that is closely related to adenosine triphosphate (ATP), another important energy molecule in the cell. In the medical field, GTP is often studied in the context of its role in regulating the activity of proteins called G-proteins. These proteins are involved in transmitting signals from cell surface receptors to the interior of the cell, and they play a key role in many physiological processes, including the regulation of blood pressure, heart rate, and neurotransmitter release. GTP is also involved in the regulation of protein synthesis, as it is a key component of the initiation complex that forms at the beginning of the translation process. In addition, GTP is involved in the regulation of cell division, as it is required for the proper assembly and function of the mitotic spindle, which is responsible for separating the chromosomes during cell division. Overall, GTP is a critical molecule in many cellular processes, and its dysfunction can lead to a variety of diseases and disorders.
Colforsin is a synthetic decapeptide that mimics the action of adenosine, a naturally occurring molecule that plays a role in regulating various physiological processes in the body. It is used in the medical field as a bronchodilator, which means it helps to relax and widen the airways in the lungs, making it easier to breathe. Colforsin is typically administered as an aerosol or nebulizer solution and is used to treat conditions such as asthma, chronic obstructive pulmonary disease (COPD), and bronchitis. It works by activating adenosine receptors in the lungs, which leads to the release of calcium from the cells lining the airways, causing them to relax and open up.
Bacterial proteins are proteins that are synthesized by bacteria. They are essential for the survival and function of bacteria, and play a variety of roles in bacterial metabolism, growth, and pathogenicity. Bacterial proteins can be classified into several categories based on their function, including structural proteins, metabolic enzymes, regulatory proteins, and toxins. Structural proteins provide support and shape to the bacterial cell, while metabolic enzymes are involved in the breakdown of nutrients and the synthesis of new molecules. Regulatory proteins control the expression of other genes, and toxins can cause damage to host cells and tissues. Bacterial proteins are of interest in the medical field because they can be used as targets for the development of antibiotics and other antimicrobial agents. They can also be used as diagnostic markers for bacterial infections, and as vaccines to prevent bacterial diseases. Additionally, some bacterial proteins have been shown to have therapeutic potential, such as enzymes that can break down harmful substances in the body or proteins that can stimulate the immune system.
Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) is a neuropeptide that plays a role in various physiological processes in the body, including the regulation of hormone secretion, metabolism, and pain perception. It is synthesized in the hypothalamus and released into the bloodstream, where it acts on receptors in various tissues throughout the body. PACAP has been shown to stimulate the release of several hormones from the pituitary gland, including adrenocorticotropic hormone (ACTH), growth hormone (GH), and thyroid-stimulating hormone (TSH). It also has effects on the cardiovascular system, where it can cause vasodilation and lower blood pressure. In addition to its physiological effects, PACAP has been implicated in various diseases and disorders, including depression, anxiety, and pain. It is also being studied as a potential therapeutic target for these conditions.
Calcium is a chemical element with the symbol Ca and atomic number 20. It is a vital mineral for the human body and is essential for many bodily functions, including bone health, muscle function, nerve transmission, and blood clotting. In the medical field, calcium is often used to diagnose and treat conditions related to calcium deficiency or excess. For example, low levels of calcium in the blood (hypocalcemia) can cause muscle cramps, numbness, and tingling, while high levels (hypercalcemia) can lead to kidney stones, bone loss, and other complications. Calcium supplements are often prescribed to people who are at risk of developing calcium deficiency, such as older adults, vegetarians, and people with certain medical conditions. However, it is important to note that excessive calcium intake can also be harmful, and it is important to follow recommended dosages and consult with a healthcare provider before taking any supplements.
Bacillus anthracis is a Gram-positive, rod-shaped bacterium that is the causative agent of anthrax, a serious infectious disease that can affect humans and animals. Anthrax can present in several forms, including cutaneous (skin), inhalation (lung), and gastrointestinal anthrax. In humans, cutaneous anthrax is the most common form and typically occurs after exposure to contaminated soil or animal products. Inhalation anthrax is the most severe form and can be fatal if not treated promptly. Gastrointestinal anthrax is rare and typically occurs after consuming contaminated meat or milk. B. anthracis is a highly infectious organism that can be spread through the air, contact with contaminated materials, or ingestion of contaminated food or water. The bacteria produce a potent toxin that can cause severe inflammation and damage to tissues, leading to symptoms such as fever, chills, nausea, vomiting, and difficulty breathing. Treatment for anthrax typically involves antibiotics, such as penicillin or ciprofloxacin, and supportive care to manage symptoms. In severe cases, hospitalization and intensive care may be necessary. Vaccines are also available to prevent anthrax, and post-exposure prophylaxis can be given to individuals who have been exposed to the bacteria.
Guanosine triphosphate (GTP) is a nucleotide that plays a crucial role in various cellular processes, including energy metabolism, signal transduction, and protein synthesis. It is composed of a guanine base, a ribose sugar, and three phosphate groups. In the medical field, GTP is often studied in relation to its role in regulating cellular processes. For example, GTP is a key molecule in the regulation of the actin cytoskeleton, which is responsible for maintaining cell shape and facilitating cell movement. GTP is also involved in the regulation of protein synthesis, as it serves as a substrate for the enzyme guanine nucleotide exchange factor (GEF), which activates the small GTPase protein Rho. In addition, GTP is involved in the regulation of various signaling pathways, including the Ras/MAPK pathway and the PI3K/Akt pathway. These pathways play important roles in regulating cell growth, differentiation, and survival, and are often dysregulated in various diseases, including cancer. Overall, GTP is a critical molecule in cellular metabolism and signaling, and its dysfunction can have significant consequences for cellular function and disease.
Fluorides are compounds that contain the fluoride ion (F-). In the medical field, fluorides are commonly used to prevent tooth decay and improve oral health. They can be found in a variety of products, including toothpaste, mouthwashes, and fluoride supplements. Fluoride works by strengthening tooth enamel, making it more resistant to acid attacks from bacteria in the mouth. It can also help to remineralize tooth enamel that has already been damaged by acid. Fluoride is also used in water treatment to reduce the risk of tooth decay in communities. In addition, fluoride is sometimes used in dental procedures, such as fluoride varnishes and fluoride gels, to further strengthen teeth and prevent decay. While fluoride is generally considered safe and effective, excessive exposure to fluoride can lead to dental fluorosis, a condition that causes white or brown stains on the teeth. It is important to use fluoride products in moderation and to follow the instructions on the label.
Isoproterenol is a synthetic beta-adrenergic agonist that is used in the medical field as a medication. It is a drug that mimics the effects of adrenaline (epinephrine) and can be used to treat a variety of conditions, including asthma, heart failure, and bradycardia (a slow heart rate). Isoproterenol works by binding to beta-adrenergic receptors on the surface of cells, which triggers a cascade of events that can lead to increased heart rate, relaxation of smooth muscle, and dilation of blood vessels. This can help to improve blood flow and oxygen delivery to the body's tissues, and can also help to reduce inflammation and bronchoconstriction (narrowing of the airways). Isoproterenol is available in a variety of forms, including tablets, inhalers, and intravenous solutions. It is typically administered as a short-acting medication, although longer-acting formulations are also available. Side effects of isoproterenol can include tremors, palpitations, and increased heart rate, and the drug may interact with other medications that affect the heart or blood vessels.
Sodium fluoride is a chemical compound that is commonly used in the medical field as a fluoride supplement to prevent tooth decay. It is also used in dental products such as toothpaste and mouthwash to help strengthen tooth enamel and prevent cavities. In the medical field, sodium fluoride is typically administered as a solution or tablet to patients who are at risk of developing tooth decay. It is also used in certain medical treatments, such as radiation therapy, to help prevent the development of new blood vessels in tumors. Sodium fluoride is generally considered safe when used as directed, but high doses or prolonged exposure can be harmful. It is important to follow the recommended dosage and use caution when administering sodium fluoride to patients, especially children.
GTP-binding proteins, also known as G proteins, are a family of proteins that play a crucial role in signal transduction in cells. They are involved in a wide range of cellular processes, including cell growth, differentiation, and metabolism. G proteins are composed of three subunits: an alpha subunit, a beta subunit, and a gamma subunit. The alpha subunit is the one that binds to guanosine triphosphate (GTP), a molecule that is involved in regulating the activity of the protein. When GTP binds to the alpha subunit, it causes a conformational change in the protein, which in turn activates or inhibits downstream signaling pathways. G proteins are activated by a variety of extracellular signals, such as hormones, neurotransmitters, and growth factors. Once activated, they can interact with other proteins in the cell, such as enzymes or ion channels, to transmit the signal and initiate a cellular response. G proteins are found in all eukaryotic cells and play a critical role in many physiological processes. They are also involved in a number of diseases, including cancer, neurological disorders, and cardiovascular diseases.
Calmodulin is a small, calcium-binding protein that plays a crucial role in regulating various cellular processes in the body. It is found in all eukaryotic cells and is involved in a wide range of physiological functions, including muscle contraction, neurotransmitter release, and gene expression. Calmodulin is a tetramer, meaning that it is composed of four identical subunits, each of which contains two EF-hand calcium-binding domains. When calcium ions bind to these domains, the structure of calmodulin changes, allowing it to interact with and regulate the activity of various target proteins. In the medical field, calmodulin is often studied in the context of various diseases and disorders, including cardiovascular disease, cancer, and neurological disorders. For example, abnormal levels of calmodulin have been associated with the development of certain types of cancer, and calmodulin inhibitors have been investigated as potential therapeutic agents for treating these diseases. Additionally, calmodulin has been implicated in the pathogenesis of various neurological disorders, including Alzheimer's disease and Parkinson's disease.
Receptors, Adrenergic, beta (β-adrenergic receptors) are a type of protein found on the surface of cells in the body that bind to and respond to signaling molecules called catecholamines, including adrenaline (epinephrine) and noradrenaline (norepinephrine). These receptors are part of the adrenergic signaling system, which plays a critical role in regulating a wide range of physiological processes, including heart rate, blood pressure, metabolism, and immune function. There are three main types of β-adrenergic receptors: β1, β2, and β3. Each type of receptor is found in different tissues and has different functions. For example, β1 receptors are primarily found in the heart and are responsible for increasing heart rate and contractility. β2 receptors are found in the lungs, blood vessels, and muscles, and are involved in relaxing smooth muscle and increasing blood flow. β3 receptors are found in adipose tissue and are involved in regulating metabolism. Activation of β-adrenergic receptors can have a variety of effects on the body, depending on the specific receptor subtype and the tissue it is found in. For example, activation of β2 receptors in the lungs can cause bronchodilation, which can help to open up airways and improve breathing in people with asthma or other respiratory conditions. Activation of β1 receptors in the heart can increase heart rate and contractility, which can help to improve blood flow and oxygen delivery to the body's tissues. Activation of β3 receptors in adipose tissue can increase metabolism and help to promote weight loss. β-adrenergic receptors are important therapeutic targets for a variety of medical conditions, including heart disease, asthma, and diabetes. Drugs that target these receptors, such as beta blockers and beta agonists, are commonly used to treat these conditions.
Alprostadil is a medication that is used to treat a variety of medical conditions, including erectile dysfunction (ED), Raynaud's disease, and pulmonary hypertension. It is a synthetic version of a hormone called prostaglandin E1 (PGE1), which is naturally produced by the body and plays a role in regulating blood flow and maintaining normal blood pressure. Alprostadil is typically administered as a suppository, injection, or gel, and works by relaxing the smooth muscles in blood vessels, allowing blood to flow more freely and improving blood flow to the penis or other affected areas. It is often used in combination with other medications or treatments, such as phosphodiesterase type 5 inhibitors (PDE5 inhibitors) or vacuum therapy, to enhance their effectiveness. Alprostadil can cause side effects, including headache, flushing, nausea, and dizziness. It is important to follow the instructions provided by your healthcare provider and to report any side effects to them immediately.
The cell membrane, also known as the plasma membrane, is a thin, flexible barrier that surrounds and encloses the cell. It is composed of a phospholipid bilayer, which consists of two layers of phospholipid molecules arranged tail-to-tail. The hydrophobic tails of the phospholipids face inward, while the hydrophilic heads face outward, forming a barrier that separates the inside of the cell from the outside environment. The cell membrane also contains various proteins, including channels, receptors, and transporters, which allow the cell to communicate with its environment and regulate the movement of substances in and out of the cell. In addition, the cell membrane is studded with cholesterol molecules, which help to maintain the fluidity and stability of the membrane. The cell membrane plays a crucial role in maintaining the integrity and function of the cell, and it is involved in a wide range of cellular processes, including cell signaling, cell adhesion, and cell division.
Adenosine diphosphate ribose (ADPR) is a naturally occurring nucleotide that plays a role in various cellular processes, including energy metabolism, signal transduction, and gene expression. It is composed of an adenosine base, a ribose sugar, and two phosphate groups. In the medical field, ADPR is often studied in relation to its role in the regulation of cellular energy metabolism. For example, ADPR is involved in the production of ATP, the primary energy currency of the cell, through a process called substrate-level phosphorylation. ADPR is also involved in the regulation of calcium signaling, which is important for a wide range of cellular processes, including muscle contraction, neurotransmitter release, and gene expression. In addition, ADPR has been implicated in various diseases, including cancer, cardiovascular disease, and neurodegenerative disorders. For example, ADPR has been shown to regulate the activity of certain enzymes involved in cell proliferation and survival, which may contribute to the development of cancer. ADPR has also been shown to play a role in the regulation of blood vessel function, which may be important for the prevention and treatment of cardiovascular disease. Finally, ADPR has been implicated in the pathogenesis of neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease, through its effects on calcium signaling and gene expression.
T-2 Toxin is a type of mycotoxin produced by certain species of fungi, including Fusarium and Aspergillus. It is commonly found in cereals, grains, and other agricultural products, and can cause a range of health problems in humans and animals if ingested in sufficient quantities. In the medical field, T-2 Toxin is considered a potential hazard to human health, particularly in cases of food poisoning. It can cause a variety of symptoms, including nausea, vomiting, diarrhea, abdominal pain, and fever. In severe cases, it can lead to more serious health problems, such as liver and kidney damage, and even death. T-2 Toxin is also a concern in veterinary medicine, as it can cause illness and death in livestock if they consume contaminated feed. In addition, it can have negative effects on the growth and development of animals, as well as on their reproductive systems. To prevent the occurrence of T-2 Toxin poisoning, it is important to properly store and handle agricultural products, and to monitor them for signs of fungal contamination. In cases where contamination is suspected, it may be necessary to remove the contaminated products from the food supply and to take steps to prevent further contamination.
Prostaglandins E (PGE) are a group of lipid signaling molecules that are produced in the body from arachidonic acid. They are synthesized by enzymes called cyclooxygenases (COX) and are involved in a wide range of physiological processes, including inflammation, pain, fever, and blood clotting. PGEs are produced in response to various stimuli, such as injury, infection, or stress, and act as messengers to regulate cellular responses. They can also act as vasodilators, increasing blood flow to tissues, and as bronchodilators, relaxing smooth muscle in the airways. In the medical field, PGEs are used as drugs to treat a variety of conditions, including pain, inflammation, and asthma. They are also used in research to study the mechanisms of these processes and to develop new treatments.
Guanine nucleotides are a type of nucleotide that contains the nitrogenous base guanine. They are important components of DNA and RNA, which are the genetic material of all living organisms. In DNA, guanine nucleotides are paired with cytosine nucleotides to form the base pair G-C, which is one of the four possible base pairs in DNA. In RNA, guanine nucleotides are paired with uracil nucleotides to form the base pair G-U. Guanine nucleotides play a crucial role in the structure and function of DNA and RNA, and are involved in many important biological processes, including gene expression, DNA replication, and protein synthesis.
1-Methyl-3-isobutylxanthine, also known as IBMX, is a chemical compound that belongs to the xanthine family. It is a selective inhibitor of the enzyme phosphodiesterase type 4 (PDE4), which is involved in the breakdown of cyclic AMP (cAMP) in cells. In the medical field, IBMX is used as a research tool to study the effects of PDE4 inhibition on various physiological processes, including inflammation, pain, and airway smooth muscle contraction. It has also been investigated as a potential treatment for a variety of conditions, including asthma, chronic obstructive pulmonary disease (COPD), and psoriasis. However, IBMX is not currently approved for use as a therapeutic agent in humans, as it can have significant side effects, including nausea, vomiting, diarrhea, and increased heart rate. Additionally, prolonged use of IBMX can lead to the development of tolerance and dependence.
Receptors, Adrenergic are a type of protein found on the surface of cells in the body that bind to and respond to adrenergic hormones, such as adrenaline and noradrenaline. These hormones are produced by the adrenal gland and are involved in the body's "fight or flight" response to stress. When adrenergic hormones bind to their receptors, they trigger a series of chemical reactions within the cell that can have a wide range of effects on the body, including increasing heart rate, blood pressure, and metabolism. Adrenergic receptors are classified into two main types: alpha receptors and beta receptors, which have different effects on the body.
Thionucleotides are a type of nucleotide that contain a sulfur atom in place of the oxygen atom that is typically found in the sugar-phosphate backbone of nucleotides. They are an important component of the genetic material of certain bacteria and archaea, and are also used in the synthesis of certain drugs and other compounds. Thionucleotides are synthesized using a variety of methods, including chemical synthesis and enzymatic synthesis. They have a number of unique properties that make them useful in a variety of applications, including their ability to form stable bonds with other molecules and their ability to undergo a variety of chemical reactions.
Dideoxyadenosine (ddA) is a nucleoside analog that is used in the treatment of certain viral infections, particularly HIV and hepatitis B. It works by inhibiting the activity of the viral reverse transcriptase enzyme, which is essential for the replication of these viruses. ddA is typically administered as a part of combination therapy with other antiretroviral drugs. It is also being studied for its potential use in the treatment of other viral infections and cancer.
Adenylate cyclase toxin
Alfred G. Gilman
List of MeSH codes (D08)
Cyclic adenosine monophosphate
List of MeSH codes (D23)
Heat-labile enterotoxin family
Cannabinoid receptor 1
Formyl peptide receptor 2
Adenylate cyclase toxin - Wikipedia
Calmodulin-induced conformational and hydrodynamic changes in the catalytic domain of Bordetella pertussis adenylate cyclase...
Table 1 - Bordetella petrii Infection with Long-lasting Persistence in Human - Volume 17, Number 4-April 2011 - Emerging...
Daniel Ladant - Search Results - PubMed
Cholera: Background, Pathophysiology, Etiology
User:Schuylerjones - microbewiki
Publications - School of Biochemistry and Immunology - Trinity College Dublin
Frontiers | The Role of Mucosal Immunity in Pertussis
Overview of Gastroenteritis - Gastrointestinal Disorders - MSD Manual Professional Edition
Application of impedance measurement to investigate in vitro inhalation toxicity of bacteria | Journal of Occupational Medicine...
A process and almost the final stage; it - Free Argumentative Essays For Students
Pesquisa | Biblioteca Virtual em Saúde - BRASIL
Toxin - Wikipedia
Acute Gastroenteritis - DocShare.tips
CDC Science Clips
Pertussis Test: Reference Range, Interpretation, Collection and Panels
DeCS 2020 - June 23, 2020 version
EurekaMag PDF full texts Chapter 28685
DeCS 2019 - June 12, 2019 version
DeCS 2018 - July 31, 2018 version
DeCS 2017 - July 04, 2017 version
DeCS 2018 - July 31, 2018 version
What Is the Endocannabinoid System? - Plant People
Bacillus | Taber's Medical Dictionary
Defensive immunity against toxin A induced by dental immunization using a live, attenuated vector strain - drug discovery and...
Food Poisoning Workup: Laboratory Studies, Imaging Studies, Procedures
- Together with the pertussis toxin it is the most important virulence factor of the causative agent of whooping cough, Bordetella pertussis. (wikipedia.org)
- Bordetella bronchiseptica and Bordetella parapertussis, also able to cause pertussis-like symptoms, also produce adenylate cyclase toxin. (wikipedia.org)
- Adenylate cyclase toxin from Bordetella pertussis is a 1706 amino acid residue long protein. (wikipedia.org)
- Bordetella pertussis, the causative agent of whooping cough, secretes among various toxins an adenylate cyclase (CyaA) that displays a unique mechanism of cell invasion, which involves a direct translocation of its N-terminal catalytic domain (AC, 400 residues) across the plasma membrane of the eukaryotic targeted cells. (pasteur.fr)
- Bioengineering of Bordetella pertussis Adenylate Cyclase Toxin for Vaccine Development and Other Biotechnological Purposes. (nih.gov)
- However, "B. bronchiseptica" has the genes to express the toxin which shows that "B. bronchiseptica" is closely related to "B. pertussis" . (kenyon.edu)
- A known bacterial toxin, which has a health adverse effect in the lungs, is the pertussis toxin from Bordetella pertussis . (biomedcentral.com)
- pertussis toxin, pertactin, filamentous hemagglutinin and fimbrial antigens 2/3, and adenylate cyclase toxin in a single reaction (5-plex) with a calibrated reference standard, QC reagents and SAS((R)) based data analysis program. (cdc.gov)
- With the addition of adenosine diphosphate-ribose onto the inhibitory G protein, adenylate cyclase is stimulated by the pertussis toxin, which has 2 components: subunit A and subunit B. Subunit A has the adenosine diphosphate-ribosylating activity. (medscape.com)
- Recent evidence, however, has supported a mechanism involving a G protein-coupled receptor found in brain and neural cell lines, and which inhibits adenylate cyclase activity in a dose-dependent, stereoselective and pertussis toxin-sensitive manner. (plantpeople.co)
- Pertussis toxin uncoupling-based studies have shown that Gαi and Gαo can inhibit insulin secretion in pancreatic β-cells. (diabetesjournals.org)
- They vary greatly in their toxicity , ranging from usually minor (such as a bee sting ) to potentially fatal even at extremely low doses (such as botulinum toxin ). (wikipedia.org)
- 2002 Recently botulinum toxin has been found to be an effective preventative (Rapoport 2010 Despite these options many migraineurs do not respond to medication (Tfelt-Hansen and Olesen 2012 or develop chronic daily headaches due to medication overuse (Bussone 2010 Current understanding of migraine pathophysiology The lack LY335979 of therapeutic options in managing migraine reflects the limited understanding of the mechanisms behind migraine. (sciencepop.org)
- The part of the toxin from residue 400 to the C-terminus, called hemolysin, is structurally related to a large family of bacterial toxins - RTX toxins. (wikipedia.org)
- In this study, we analyzed three bacterial toxins and five culture supernatants of selected bacteria with known toxicity as model agents exposed to the lung epithelial cell line NuLi-1. (biomedcentral.com)
- Another example, the alpha-toxin of Staphylococcus aureus is also involved in pneumonia and attacks pulmonary epithelial cells. (biomedcentral.com)
- The toxin forms transmembrane pores, which leads to the collapse of the cells and epithelial cells can no longer exercise their barrier function [ 6 ]. (biomedcentral.com)
- These enterotoxins stimulate the adenylate cyclase-cyclic adenosine monophosphate system in intestinal epithelial cells, leading to profuse watery diarrhea. (unboundmedicine.com)
- Subunit B binds the toxin to the cell surface receptors, thereby inhibiting chemokine receptors, with the result being lymphocytosis. (medscape.com)
- The alpha subunit of the Gprotein deactivates adenylate cyclase while the betagamma subunit activates the Kchannels and therefore hyperpolarise the cell. (wikidoc.org)
- We confirmed concentration dependent cytotoxic effects of the selected toxins in NuLi-1 cells over a period of up to 48 h. (biomedcentral.com)
- The toxin is secreted by the Type I secretion system, which spans both membranes and periplasm space, allowing the toxin to be secreted from the cytoplasm straight outside the cell. (wikipedia.org)
- ATCC CRL 1476) exhibited low levels of beta-adrenergic receptors as determined by specific binding of [125I]cyanopindolol ([125I]CYP) and marginal stimulation of adenylate cyclase in plasma membranes by (-)isoproterenol. (shengsci.com)
- The abilities of lipophilic cannabinoid drugs to regulate adenylate cyclase activity in neuroblastoma cell membranes were analyzed by thermodynamic studies. (shengsci.com)
- As a cellular energy sensor, AMP - activated protein kinase ( AMPK ) is activated in response to a variety of conditions that deplete cellular energy levels, such as nutrient starvation (especially glucose), hypoxia and exposure to toxins that inhibit the mitochondrial respiratory chain complex. (drrestivo.com)
- The transiently opened pores do, however, contribute to AC domain function by potassium leakage and calcium influx into the target cell, which slows endocytosis of CR3/adenylate cyclase toxin clusters, also, the CR3/toxin complex is mobilized by detachment from the cytoskeleton. (wikipedia.org)
- Adenylate cyclase toxin binds to target cells by the complement receptor 3 (CD11b/CD18, or Mac-1). (wikipedia.org)
- Translocation of the AC domain into the cell starts the main process by which this toxin influences target cells: the AC domain binds calmodulin, and catalyzes unregulated production of cAMP from ATP. (wikipedia.org)
- Toxins can be small molecules , peptides , or proteins that are capable of causing disease on contact with or absorption by body tissues interacting with biological macromolecules such as enzymes or cellular receptors . (wikipedia.org)
- Furthermore, this citrus fruit contains a high level of antioxidants, which can assist the body in flushing out toxins and fat without complete absorption. (consumerhealthdigest.com)
- A large proportion of the toxin remains associated with the bacterium exterior proteins, mainly filamentous haemagglutinin, but these toxin molecules are not active. (wikipedia.org)
- Besides attachment to bacterial proteins, aggregation also inactivates the toxin. (wikipedia.org)
- Within certain cells the enzyme adenylate cyclase makes cAMP from ATP, and typically this reaction is regulated by hormones such as adrenaline or glucagon. (drrestivo.com)
- B. bronchiseptica" also produces many toxins such as bifunctional adenylate cyclase and dermonecrotic toxins. (kenyon.edu)
- The cell types which are vulnerable to this pore-forming activity varies among the toxins. (wikipedia.org)
- Translocation of the AC domain is independent of cytotoxic pore-forming activity, as these two activities require to toxin to adopt different conformations. (wikipedia.org)
- The adenylate cyclase domain has intrinsic enzymatic activity. (wikipedia.org)
- Each toxin resulted in a different but specific impedance profile over time according to their mode of action, whereas viability assay showed the metabolic activity of the cells at a chosen time point without revealing any information on their mode of action. (biomedcentral.com)
- Arrhenius plots of hormone-stimulated adenylate cyclase activity exhibited a break point at 20 degrees. (shengsci.com)
- The above described effects of the adenylate cyclase toxin, mainly the cAMP overproduction, have a profound effect on target cells. (wikipedia.org)
- A toxin is a naturally occurring organic poison  produced by metabolic activities of living cells or organisms . (wikipedia.org)
- Intoxication with the adenylate cyclase toxin leads to shift in polarization of macrophages from M1 (proinflammatory) phenotype to M2 (immunoregulatory) phenotype and may lead to macrophage apoptosis. (wikipedia.org)
- Toxins are often distinguished from other chemical agents strictly based on their biological origin. (wikipedia.org)
- Regulation of adenylate cyclase by cannabinoid drugs. (shengsci.com)
- Post-translational acylation controls the folding and functions of the CyaA RTX toxin. (nih.gov)
-  They can also be classified by their source, such as fungal biotoxins , microbial toxins , plant biotoxins , or animal biotoxins. (wikipedia.org)
- Toxins produced by microorganisms are important virulence determinants responsible for microbial pathogenicity and/or evasion of the host immune response . (wikipedia.org)
- The term toxungen has also been proposed to refer to toxins that are delivered onto the body surface of another organism without an accompanying wound . (wikipedia.org)