TY - JOUR. T1 - Characterization of apical and basolateral plasma membrane domains derived from cultured rat cholangiocytes. AU - Tietz, Pamela. AU - Levine, Susan. AU - Holman, Ralph. AU - Fretham, Chris. AU - La Russo, Nicholas F. PY - 1997/12/15. Y1 - 1997/12/15. N2 - Cholangiocytes, the epithelial cells that line intrahepatic bile ducts, are composed of plasma membranes with discrete apical (lumenal) and basolateral domains that contain different channels, transporters, and receptors. In recent work, we developed a long-term, primary culture system of normal rat cholangiocytes (NRC). Our aims here were to prepare and characterize apical and basolateral plasma membrane vesicles from NRC. Using serial isopycnic centrifugation on sucrose gradients, we generated separate apical and basolateral plasma membrane vesicles. We characterized these vesicles by transmission electron microscopy, specific marker enzyme assays, and immunoblotting; we also determined the percentage of sealed vesicles and ...
Al, hamdani M.; Atkinson, M E.; and Mayhew, T M., Changes in the plasma membrane surface of lymphocytes stimulated in vivo with dncb. (1979). Subject Strain Bibliography 1979. 2522 ...
TY - JOUR. T1 - Loss of cytoskeletal support is not sufficient for anoxic plasma membrane disruption in renal cells. AU - Chen, Jing. AU - Dai, Jianwu. AU - Grant, Roberta L.. AU - Doctor, R. Brian. AU - Sheetz, Michael. AU - Mandel, Lazaro J.. PY - 1997/5/21. Y1 - 1997/5/21. N2 - The goal of this study was to determine whether anoxic membrane disruption is initiated by loss of cytoskeletal support in rabbit renal proximal tubules (PT). We specifically tested 1) whether cytoskeletal perturbation affects membrane integrity under normoxia, 2) whether cytoskeletal perturbation potentiates anoxic membrane damage, and 3) whether the membrane protection by glycine depends on cytoskeletal integrity. Cytoskeletal perturbation was achieved with 10 μM cytochalasin D (CD) because it selectively disturbs F-actin organization and has similar effects as anoxia on the cytoskeleton of PT. During normoxia, CD caused decreased basal F-actin content, microvillar breakdown, and membrane-cytoskeleton dissociation, ...
BackgroundIngestion of the lectins present in certain improperly cooked vegetables can result in acute GI tract distress, but the mechanism of toxicity is unknown. In vivo, gut epithelial cells are constantly exposed to mechanical and other stresses and consequently individual cells frequently experience plasma membrane disruptions. Repair of these cell surface disruptions allows the wounded cell to survive: failure results in necrotic cell death. Plasma membrane repair is mediated, in part, by an exocytotic event that adds a patch of internal membrane to the defect site. Lectins are known to inhibit exocytosis. We therefore tested the novel hypothesis that lectin toxicity is due to an inhibitory effect on plasma membrane repair.Methods and FindingsRepair of plasma membrane disruptions and exocytosis of mucus was assessed after treatment of cultured cell models and excised segments of the GI tract with lectins. Plasma membrane disruptions were produced by focal irradiation of individual cells, using a
1. A liver canalicular plasma-membrane fraction enriched 115-155-fold in five marker enzymes relative to the tissue homogenate was obtained by sonication of liver plasma membranes followed by fractionation in iso-osmotic Nycodenz gradients. 2. Two lateral-plasma membrane fractions were also collected by this procedure; the lighter-density fraction was still associated with canalicular membranes, as assessed by enzymic and polypeptide analysis. 3. The polypeptide composition of the domain-defined plasma-membrane fractions was evaluated. It was demonstrated by immunoblotting that the 41 kDa alpha-subunit of the inhibitory G-protein, associated in high relative amounts with canalicular plasma-membrane fractions, was partially lost in the last stage of purification; however, this subunit was retained by lateral plasma membranes. 4. Antibodies to the proteins of bile-canalicular vesicles were shown to localize to the hepatocyte surface in thin liver sections examined by immunofluorescent and ...
Cell-free studies have demonstrated how collective action of actin-associated proteins can organize actin filaments into dynamic patterns, such as vortices, asters and stars. Using complementary microscopic techniques, we here show evidence of such self-organization of the actin cortex in living HeLa cells. During cell adhesion, an active multistage process naturally leads to pattern transitions from actin vortices over stars into asters. This process is primarily driven by Arp2/3 complex nucleation, but not by myosin motors, which is in contrast to what has been theoretically predicted and observed in vitro. Concomitant measurements of mechanics and plasma membrane fluidity demonstrate that changes in actin patterning alter membrane architecture but occur functionally independent of macroscopic cortex elasticity. Consequently, tuning the activity of the Arp2/3 complex to alter filament assembly may thus be a mechanism allowing cells to adjust their membrane architecture without affecting their
Plasma membrane-derived vesicles (PMVs) are released into circulation in response to normal and stress/pathogenic conditions. They are of tremendous significance for the prediction, diagnosis, and observation of the therapeutic success of many diseases. Knowledge of their molecular characteristics and therefore functional properties would contribute to a better understanding of the pathological mechanisms leading to various diseases in which their levels are raised. The review aims at outlining and discussing the molecular characteristics of PMVs in order to bring to the fore some aspects/characteristics of PMVs that will assist the scientific community to properly understand the role of PMVs in various physiological and pathological processes. The review covers PMVs characterisation and discusses how distinct they are from exosomes and endosomes. Also, methods of PMVs analysis, importance of proper PMV level estimation/characterisation, PMVs and their constituents as well as their therapeutic
Considerable controversy arose over the concept that cholesterol/sphingolipid-rich rafts in the T cell plasma membrane serve as a platform for TCR signalling reactions. This controversy was founded on the initial definition of rafts as detergent resistant membranes which later turned out to misrepresent many features of cell membrane organisation under physiological conditions. Raft-organisation was subsequently studied using a number of detergent-free experimental approaches. The results led to a refined perception of membrane rafts which resolves the controversies. Here we review new biophysical and biochemical data which provide an updated picture of the highly dynamic nanometer-sized cholesterol/sphingolipid-rich raft domains stabilised by protein-networks to form TCR signalling platforms in the T cell plasma membrane.
Plasma membrane-derived vesicles (PMVs) are released into circulation in response to normal and stress/pathogenic conditions. They are of tremendous significance for the prediction, diagnosis, and observation of the therapeutic success of many diseases. Knowledge of their molecular characteristics and therefore
Cell membranes are structured so that molecules can pass in and out of the cell across them. While both plant and animal cells have membranes, plant...
Cell membranes are structures of contradictions. These oily films are hundreds of times thinner than a strand of spider silk, yet strong enough to protect the delicate contents of life: the cells watery cytoplasm, genetic material, organelles, and all the molecules it needs to survive. How does the membrane work, and where does that strength come from? Nazzy Pakpour investigates ...
The distribution of [3H]leukotriene D4 [( 3H]LTD4) receptors in subcellular membrane fractions obtained from sheep tracheal smooth muscle was studied. Using differential centrifugation and discontinuous sucrose density gradient centrifugation, the subcellular membranes were separated into six fractions. The [3H]LTD4 receptor distribution profile in these fractions correlated with markers for the plasma membrane (5-nucleotidase and alkaline phosphodiesterase) and did not correlate with markers for the mitochondria (cytochrome c oxidase and succinate-dependent cytochrome c reductase). The dissociation constant (Kd) and maximum number of binding sites (Bmax) for [3H]LTD4 binding to the receptors in the crude mixture of membranes (PII) were 0.38 +/- 0.2 nM and 77 +/- 14 fmol/mg of protein, respectively. The Kd and Bmax of [3H]LTD4 binding to the receptors in the plasma membrane-enriched fraction (FII) were 0.40 +/- 0.2 nM and 268 +/- 46 fmol/mg of protein, respectively. The specificity profile of ...
Plasma membrane-enriched fractions were isolated from human gliomas and brain white matter. These membrane fractions were characterized by electron microscopy and by the distribution of the membrane...
Norma Andrews (UMCP) 1: Mechanisms of Plasma Membrane Repair Dr. Norma Andrews overviews the mechanisms of cellular plasma membrane repair. Part 1: Mechanisms of Plasma Membrane Repair: Norma Andrews overviews the
Antibodies for proteins involved in cytoskeletal anchoring at plasma membrane pathways, according to their Panther/Gene Ontology Classification
DC-Research Knowledge Portal: Transcriptional analysis of the integral plasma membrane proteome of D1 cells stimulated with LPS harvested at different time-points
In this study, we identified a novel domain, the EFC domain, which is related to the BAR domain. Half of the EFC domain was previously characterized as an FCH domain, but an additional sequence is required for interaction with the membrane. Our results provide the first evidence that the EFC domain of FBP17 directly binds to the membrane and deforms protein-free liposomes into tubules. Moreover, the EFC domains of other PCH family proteins, such as CIP4, FER, PSTPIP1, and PSTPIP2, also strongly bind to and tubulate liposomes (Figs. 3 and 4). Conservation of both amino acid sequence and function indicate that the EFC domain is a membrane tubulation module that is dependent on lipid binding.. The SH3 domain of FBP17 and that of other EFC domain-containing proteins bind to dynamin-2 and N-WASP. Dimerized FBP17 recruited N-WASP and dynamin-2 simultaneously (Figs. 7 and 8). N-WASP and dynamin preferentially bind to PI(4,5)P2 (Ho et al., 2004; Praefcke and McMahon, 2004). The EFC domain of FBP17 binds ...
The signals that direct membrane proteins to the apical or basolateral plasma membrane domains of polarized epithelial cells are not known. Several of the class of proteins anchored in the membrane by glycosyl-phosphatidylinositol (GPI) are expressed on the apical surface of such cells. However, it is not known whether the mechanism of membrane anchorage or the polypeptide sequence provides the sorting information. The conversion of the normally basolateral vesicular stomatitis virus glycoprotein (VSV G) to a GPI-anchored protein led to its apical expression. Conversely, replacement of the GPI anchor of placental alkaline phosphatase with the transmembrane and cytoplasmic domains of VSV G shifted its expression from the apical to the basolateral surface. Thus, the mechanism of membrane anchorage can determine the sorting of proteins to the apical or basolateral surface, and the GPI anchor itself may provide an apical transport signal. ...
Voltage-gated K+ (Kv) channels play a key role in establishing the resting membrane potential, shaping action potential repolarization and regulating spike frequency in many cell types. These channels often target specific plasma membrane regions where they probably assemble into signaling complexes. However, in most cases little is known about the mechanisms responsible for this localization, even though the modulation of voltage-gated ion channel surface expression and localization probably represents a central mechanism in the regulation of cellular excitability. Given the central role that the Kv2.1 delayed rectifier plays in neurons (Du et al., 2000; Misonou et al., 2005b), the heart (Nerbonne, 2000), pancreatic β cells (Tamarina et al., 2005) and vascular smooth muscle (Coppock et al., 2001), a greater understanding of the mechanisms regulating its surface localization is essential.. As originally noted by Trimmer and colleagues (Scannevin et al., 1996), Kv2.1 is expressed primarily in ...
The production of external membrane vesicles by Gram-negative bacteria has been well documented; however, the mechanism behind the biogenesis of these vesicles remains unclear. have led to several different models describing how Gram-negative bacteria produce OMVs. Data showing that OMV lipids differ from the lipids of the OM, such as the aforementioned statement on OMVs, have led to a model in which membrane curvature is definitely induced from the build up of LPS molecules with atypical constructions or costs. LPS is the major constituent of the outer leaflet of the OM of most Gram-negative bacteria. The LPS molecules themselves are not homogeneous; the space and content material of the polysaccharide chain varies among the different molecules. It is proposed that subsets of these molecules may gather in patches along the OM, inducing higher BIIB021 examples of membrane curvature at particular locations, either due to charge repulsion [22] or their molecular shape [23]. A second, but not ...
The function of any given biological membrane is determined largely by the specific set of integral membrane proteins embedded in it, and the peripheral membrane proteins attached to the membrane surface. The activity of these proteins, in turn, can be modulated by the phospholipid composition of the membrane. The reconstitution of membrane proteins into a model membrane allows investigation of individual features and activities of a given cell membrane component. However, the activity of membrane proteins is often difficult to sustain following reconstitution, since the composition of the model phospholipid bilayer differs from that of the native cell membrane. This review will discuss the reconstitution of membrane protein activities in four different types of model membrane - monolayers, supported lipid bilayers, liposomes and nanodiscs, comparing their advantages in membrane protein reconstitution. Variation in the surrounding model environments for these four different types of membrane layer can
The function of any given biological membrane is determined largely by the specific set of integral membrane proteins embedded in it, and the peripheral membrane proteins attached to the membrane surface. The activity of these proteins, in turn, can be modulated by the phospholipid composition of the membrane. The reconstitution of membrane proteins into a model membrane allows investigation of individual features and activities of a given cell membrane component. However, the activity of membrane proteins is often difficult to sustain following reconstitution, since the composition of the model phospholipid bilayer differs from that of the native cell membrane. This review will discuss the reconstitution of membrane protein activities in four different types of model membrane - monolayers, supported lipid bilayers, liposomes and nanodiscs, comparing their advantages in membrane protein reconstitution. Variation in the surrounding model environments for these four different types of membrane layer can
The pathological importance of tumor necrosis factor (TNF)-alpha in rheumatoid arthritis (RA) is now widely accepted. Ex vivo data from synovial cell cultures suggest that direct cell contact between activated T-cells and macrophages may be an important driver of macrophage TNF-alpha production in the RA joint. However, the ligand/receptor pairs driving this cell contact signal remain obscure. One reason for this is that plasma membrane (PM) proteins are resistant to systematic analysis using traditional proteomic approaches. In this chapter we present a method for the enrichment and resolution of PM proteins from murine T-cell hybridomas as a prelude to identification by tandem mass spectrometry. We used cell surface biotinylation, differential centrifugation and subsequent streptavidin affinity capture, followed by solution phase iso-electric focussing and tandem mass spectrometry to identify 75 PM proteins and make semiquantitative comparisons of resting and activated cells. The method is applicable
The connection between T cell activation, plasma membrane order and actin filament dynamics was the main focus of this study. Laurdan and di-4-ANEPPDHQ, membrane order sensing probes, were shown to report only on lipid packing rather than being influenced by the presence of membrane-inserted peptides justifying their use in membrane order studies. These dyes were used to follow plasma membrane order in live cells at 37°C. Disrupting actin filaments had a disordering effect while stabilizing actin filaments had an ordering effect on the plasma membrane, indicating there is a basal level of ordered domains in resting cells. Lowering PI(4,5)P2 levels decreased the proportion of ordered domains strongly suggesting that the connection of actin filaments to the plasma membrane is responsible for the maintaining the level of ordered membrane domains. Membrane blebs, which are detached from the underlying actin filaments, contained a low fraction of ordered domains. Aggregation of membrane components ...
enerated within this study cGKI-deficient mice. None of our antisera detected certain phospho-cGKI signals in the freshly isolated tissues (information not
TY - JOUR. T1 - Direct effect of insulin on the synthesis of specific plasma proteins. T2 - Biphasic response of hepatocytes cultured in serum- and hormone-free medium. AU - Liang, T. J.. AU - Grieninger, G.. PY - 1981. Y1 - 1981. N2 - Monolayers of chicken embryo hepatocytes, cultured in chemically defined medium, retain the ability to synthesize a wide spectrum of plasma proteins for several days in the absence of added hormones. Addition of insulin to the medium elicited a biphasic stimulation of plasma protein synthesis: a rapid response of the synthesis of a limited number of plasma proteins (e.g., albumin and α1-globulin M), then, after prolonged exposure to the hormone, the involvement of additional plasma proteins (e.g., fibrinogen and lipoproteins). Synthesis of transferrin and a few other plasma proteins was not affected by the presence of insulin. The degree of stimulation for the most responsive plasma proteins ranged between 2- to 4-fold during the early phase and 10- and even ...
The exocyst is a protein complex that has been found to be essential for exocytosis underlying neurite outgrowth (Hsu et al., 2004). Several models have been proposed to explain how the exocyst complex promotes exocytosis, including modulating cytoskeletal activity and tethering vesicles to the plasma membrane. Targeting of the exocyst complex to spatially defined domains, such as growth cones, is expected to be essential for a focused function of the exocyst complex. In this regard, exocyst subunits have been found to associate with various scaffold proteins such as PSD95 and SAP102 that target plasma membrane proteins to specific plasma membrane subdomains (Riefler et al., 2003; Sans et al., 2003) or with plasma membrane receptors, such as the glycine receptor GLYT1 (Cubelos et al., 2005).. In this manuscript, we identify NCAM as a novel binding partner of the exocyst complex. Several studies have shown that NCAM plays an important role in neural development by regulating neurite outgrowth. In ...
One mode of regulation occurs directly at the level of Rho, where activation of Rho causes PM blebbing. This can be mediated by extracellular signals (see the next section) or by intracellular signaling cascades, such as the up-regulation of RhoA in the absence of the tumor suppressor p53 (Gadea et al., 2007). PM blebbing as a result of Rho activation can also occur indirectly via the Rac GTPase, whose activity is tightly balanced with that of Rho (Sander et al., 1999). In one such example, expression of FilGAP suppresses the activity of Rac, leading to cross talk regulation of RhoA and subsequent membrane blebbing (Ohta et al., 2006). Similar events likely explain extensive PM blebbing after overexpression of an effector loop mutant of active Rac1 (Schwartz et al., 1998) or Dictyostelium discoideum RacB (Lee et al., 2003) as well as the complete lack of Rac1 expression (Vidali et al., 2006). As indicated by the potent suppression of PM blebbing by specific inhibitors of ROCK (Table I), ...
At one time cell membranes were believed to just be envelopes surrounding cells. However, it has been nearly forty years since the structure of the cell membrane was deciphered leading to the development of the Lipid Bi-Layer Fluid Mosaic Model. In this model cell membranes are no longer seen as merely envelopes, they become dynamic structures that play critical roles in the health and detoxification of cells, and the cells unique ability to work in concert - thus keeping us in good health.. Lipids - or fats - are the main component of cell membranes. Lipids in cell membranes are actually phospholipids - or a combination of fats and phosphorus - and not just fats. They dont just sit idly by doing nothing; they contribute to every aspect of cellular energy, detoxification, and optimal function.. Healthy cell-membranes lead to healthy cells, a healthy body, plenty of energy, healthy aging, and so forth. Among other things, cell membranes incorporate hormone receptors that, if sound, will promote ...
In the present study, we identified a critical trafficking determinant in the KCNQ1 channel. Significantly, the structure is the target of several LQT1 associated mutations. The N-terminal location of the trafficking domain was unexpected because previous studies highlighted the C-terminal domain as the key determinant of subunits assembly and processing in the secretory pathway.7,8,25 Indeed, we showed that the deletion of the initial 114 residues, but not the 106 initial residues, abolished plasma membrane expression of the channel. This suggested that residues 106 to 114 may constitute an ER export signal or that the amino acid sequence beyond L114 encodes a retention motif. Studies designed to test these ideas (Figure 7) revealed that these discrete structures do not function as independent, autologous trafficking signals. Indeed, they suggest that the structural integrity of the entire region preceding the first transmembrane domain is essential for proper trafficking of the ...
Membrane reservoirs serve as membrane buffers that help redistribute membrane area when cells need to stretch or change shape and size. They are found at the cell surface as membrane superstructures varying in size from large membrane folds, to tiny membrane invaginations and caveolae (reviewed in [1]).. Cells are often subject to frequent morphological changes throughout life. For example, cellular processes like phagocytosis and migration require protrusion-driven movement and cell shape changes. At the tissue and organ level, critical biological processes such as respiration and the cardiac cycle rely on the continuous, coordinated expansion and contraction of cells.. In order to accommodate these varied changes in cell morphology, the cell membrane that contains the cell must alter morphology as well. However, cell membranes are highly inelastic. Studies have shown that the maximum elastic stretching of a membrane is only 4%, even when the cell is subjected to lytic tensions which are 100 to ...
Cell membrane function in animal cell and plant cell. Cell membrane surrounds the cytoplasm and other organelles in it. Also, it controls the entry and exit of nutrients and other microscopic entities into the cell. In both animal and plant cell. The cell (from latin cella, meaning small room) is the basic structural, functional, and biological unit of all known organisms.a cell is the smallest unit of life. The ability to develop and grow The entire cell is surrounded by a membrane which is called the cell membrane. The cell membrane is also called plasma membrane or plasmalemma. It is a feature of all cells, both prokaryotic and eukaryotic. The cell membrane embraced owo layers of polysaccharide chains that are crosslinked with the assistance of dumpy peptide chains. The cell membrane, also known as the plasma membrane, is a double layer of lipids and proteins that surrounds a cell.it separates the cytoplasm (the contents of the cell) from the external environment. Functions of cell wall in ...
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Introduction. Transport across plasma membranes In this essay I will discuss and explain the transport across plasma membranes, to do this, I shall refer to osmosis, diffusion, facilitated diffusion, active transport and finally, exocytosis and endocytosis. Like all other cellular membranes, the plasma membrane consists of both lipids and proteins. The fundamental structure of the membrane is the phospholipid bilayer, which forms a stable barrier between two aqueous compartments. In the case of the plasma membrane, these compartments are the inside and the outside of the cell. Proteins embedded within the phospholipid bilayer carry out the specific functions of the plasma membrane, including selective transport of molecules. The diagram opposite shows the fluid The plasma membrane is a selectively permeable barrier between the cell and the extracellular environment. Its permeability properties ensure that essential molecules such as glucose, amino acids, and lipids are able to readily enter the ...
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Endocytosis is a fundamental process in signaling and membrane trafficking. The formation of vesicles at the plasma membrane is mediated by the G protein dynamin that catalyzes the final fission step, the actin cytoskeleton, and proteins that sense or induce membrane curvature. One such protein, the F-BAR domain-containing protein pacsin, contributes to this process and has been shown to induce a spectrum of membrane morphologies, including tubules and tube constrictions in vitro. Full-length pacsin isoform 1 (pacsin-1) has reduced activity compared to its isolated F-BAR domain, implicating an inhibitory role for its C-terminal Src homology 3 (SH3) domain. Here we show that the autoinhibitory, intramolecular interactions in pacsin-1 can be released upon binding to the entire proline-rich domain (PRD) of dynamin-1, resulting in potent membrane deformation activity that is distinct from the isolated F-BAR domain. Most strikingly, we observe the generation of small, homogenous vesicles with the activated
TY - JOUR. T1 - The economics of neurite outgrowth - The addition of new membrane to growing axons. AU - Futerman, Anthony H.. AU - Banker, Gary A.. PY - 1996/4. Y1 - 1996/4. N2 - Recent studies have shown that axonal growth is disrupted by treatments that block the synthesis of membrane components or their delivery by microtubule-based transport. This implies that a continuous supply of newly synthesized membrane components is necessary to sustain growth. In contrast, no clear consensus has yet been achieved about the site of insertion of new membrane components in the membrane of the growing axon, despite the application of new and refined biophysical and molecular techniques to the study of this issue. Until the site of insertion of new membrane components is resolved, little progress can be made in defining the feedback mechanisms by which the supply of new membrane components is co-ordinated with the demands of growth, particularly in cases where the dynamics of neurite growth change from ...
The membrane curvature can regulate the localization of proteins with specific recognition motifs. Amphipathic alpha helices are critical membrane curvature sensors with a large range of proteins included with larger affinity for positively curved membranes through the recognition of curve defects in lipid packing. The membrane curvature dependent measurements, mostly made in vitro, are averaged across liposomes of variant diameter. These measurements reduce the accuracy and make calculation of affinity more difficult ...
Fingerprint Dive into the research topics of High-Affinity Transport of L-Glutamine by a Plasma Membrane Preparation from Rat Brain. Together they form a unique fingerprint. ...
Amazing pictures of 5 Pictures Of Animal Cell Membrane is totally great for your biological science knowledge. The image Resolution 640 x 480 px and the image size only 66 kb. Click the thumbnail to see the larger version.. Tagged with: animal cell membrane, animal cell membrane color, animal cell membrane definition, animal cell membrane diagram, animal cell membrane function, .. ...
Download Free Full-Text of an article DROUGHT-INDUCED CHILLING TOLERANCE IN CUCUMBER INVOLVES MEMBRANE STABILISATION IMPROVED BY ANTIOXIDANT SYSTEM
Monotopic proteins represent a specialized group of membrane proteins in that they are engaged in biochemical events taking place at the membrane interface. In particular, the monotopic lipid-synthesizing enzymes are able to synthesize amphiphilic lipid products by catalyzing two biochemically distinct molecules (substrates) at the membrane interface. Thus, from an evolutionary point of view, anchoring into the membrane interface enables monotopic enzymes to confer sensitivity to a changing environment by regulating their activities in the lipid biosynthetic pathways in order to maintain a certain membrane homeostasis. We are focused on a plant lipid-synthesizing enzyme DGD2 involved in phosphate shortage stress, and analyzed the potentially important lipid anchoring segments of it, by a set of biochemical and biophysical approaches. A mechanism was proposed to explain how DGD2 adjusts its activity to maintain a proper membrane. In addition, a multivariate-based bioinformatics approach was used ...
Plasma membrane(PM) protein accounts for a small fraction of total cellular protein in plants but performs a very critical role in plant physiology. Isolation and purification of PM protein from plant tissues have been traditionally done by sucrose density ultracentrifugation and aqueous two-phase partitioning. These methods, while relatively effective, require ultracentrifugation and large amount of starting material. The procedures are usually tedious and time consuming.To overcome the shortcomings, we have developed this PM isolation kit. Plant tissues are first sensitized by buffer A, homogenized, and pass through a specialized filter cartridge that allows homogenates to pass through with a zigzag path. The cell membranes are ruptured into a range of predefined size during the process. Native plasma membranes are separated from a mixture of un-ruptured cells, nuclei, cytosol and organelles by subsequent differential centrifugation and density centrifugation without using ...
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Physiology and structure of cell membrane depend on the proportion of lipids, proteins and carbohydrates. They change according to the cell type and membrane location. For example, plasma membrane of erythrocytes contain 50 % of lipids, 40 % of proteins and 10 % of carbohydrates. A similar composition is found in most of the plasma membranes of other cell types, with some exceptions. Myelin, cell membrane of glial cells that wraps axons, is composed of 80 % of lipids and 20 % of proteins, and almost no carbohydrates. Intracellular membranes usually show a higher proportion of proteins than plasma membrane. A remarkable example is the inner mitochondrial membrane, where proteins are up to 80 %. Furthermore, lipids, proteins, and carbohydrates are diverse, and membranes do not only differ in the proportion of these three molecular groups, but also in the different types of lipids, proteins, and carbohydrates that are present. Moreover, as mentioned above, membranes are continuously recycled, and ...
Question 4: [8 pts]Data for membrane mobility of three different proteins (X, Y, and Z) using fluorescent recovery afterphotobleaching (FRAP) are shown
Listing of the answers to the question: Proteins that are destined to become associated with the inner surface of the plasma membrane are:
To make use nuclear content doesnt release, you can take out serveral ul cells and stain with trypan blue. Cell with intact plasma membrane will appear as white and nucleas will appear as blue (coz prypan blue can stain nucleas but cannot pass through plasma membrane ...
DC-SIGN cell surface distribution during monocyte-derived DC development. DC-SIGN binding activity was monitored during development of monocyte-derived DCs. As