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Cellular & Molecular Biology Letters Oct 2023Membrane rafts play a crucial role in the regulation of many important biological processes. Our previous data suggest that specific interactions of flotillins with MPP1...
BACKGROUND
Membrane rafts play a crucial role in the regulation of many important biological processes. Our previous data suggest that specific interactions of flotillins with MPP1 are responsible for membrane raft domain organization and regulation in erythroid cells. Interaction of the flotillin-based protein network with specific membrane components underlies the mechanism of raft domain formation and regulation, including in cells with low expression of MPP1.
METHODS
We sought to identify other flotillin partners via the immobilized recombinant flotillin-2-based affinity approach and mass spectrometry technique. The results were further confirmed via immunoblotting and via co-immunoprecipitation. In order to study the effect of the candidate protein on the physicochemical properties of the plasma membrane, the gene was knocked down via siRNA, and fluorescence lifetime imaging microscopy and spot-variation fluorescence correlation spectroscopy was employed.
RESULTS
EFR3A was identified as a candidate protein that interacts with flotillin-2. Moreover, this newly discovered interaction was demonstrated via overlay assay using recombinant EFR3A and flotillin-2. EFR3A is a stable component of the detergent-resistant membrane fraction of HeLa cells, and its presence was sensitive to the removal of cholesterol. While silencing the EFR3A gene, we observed decreased order of the plasma membrane of living cells or giant plasma membrane vesicles derived from knocked down cells and altered mobility of the raft probe, as indicated via fluorescence lifetime imaging microscopy and spot-variation fluorescence correlation spectroscopy. Moreover, silencing of EFR3A expression was found to disturb epidermal growth factor receptor and phospholipase C gamma phosphorylation and affect epidermal growth factor-dependent cytosolic Ca concentration.
CONCLUSIONS
Altogether, our results suggest hitherto unreported flotillin-2-EFR3A interaction, which might be responsible for membrane raft organization and regulation. This implies participation of this interaction in the regulation of multiple cellular processes, including those connected with cell signaling which points to the possible role in human health, in particular human cancer biology.
Topics: Humans; Cell Membrane; Epidermal Growth Factor; HeLa Cells; Protein Binding; Membrane Microdomains; Adaptor Proteins, Signal Transducing; Membrane Proteins
PubMed: 37880612
DOI: 10.1186/s11658-023-00497-y -
Journal of Microbiology (Seoul, Korea) Mar 2016Candida albicans is a human fungal pathogen capable of causing lethal systemic infections. The plasma membrane plays key roles in virulence because it not only functions... (Review)
Review
Candida albicans is a human fungal pathogen capable of causing lethal systemic infections. The plasma membrane plays key roles in virulence because it not only functions as a protective barrier, it also mediates dynamic functions including secretion of virulence factors, cell wall synthesis, invasive hyphal morphogenesis, endocytosis, and nutrient uptake. Consistent with this functional complexity, the plasma membrane is composed of a wide array of lipids and proteins. These components are organized into distinct domains that will be the topic of this review. Some of the plasma membrane domains that will be described are known to act as scaffolds or barriers to diffusion, such as MCC/eisosomes, septins, and sites of contact with the endoplasmic reticulum. Other zones mediate dynamic processes, including secretion, endocytosis, and a special region at hyphal tips that facilitates rapid growth. The highly organized architecture of the plasma membrane facilitates the coordination of diverse functions and promotes the pathogenesis of C. albicans.
Topics: Candida albicans; Candidiasis; Cell Membrane; Endocytosis; Fungal Proteins; Humans; Hyphae; Models, Molecular; Virulence; Virulence Factors
PubMed: 26920878
DOI: 10.1007/s12275-016-5621-y -
Wiley Interdisciplinary Reviews.... Sep 2017Systems biology and systems medicine have played an important role in the last two decades in shaping our understanding of biological processes. While systems biology is... (Review)
Review
Systems biology and systems medicine have played an important role in the last two decades in shaping our understanding of biological processes. While systems biology is synonymous with network maps and '-omics' approaches, it is not often associated with mechanical processes. Here, we make the case for considering the mechanical and geometrical aspects of biological membranes as a key step in pushing the frontiers of systems biology of cellular membranes forward. We begin by introducing the basic components of cellular membranes, and highlight their dynamical aspects. We then survey the functions of the plasma membrane and the endomembrane system in signaling, and discuss the role and origin of membrane curvature in these diverse cellular processes. We further give an overview of the experimental and modeling approaches to study membrane phenomena. We close with a perspective on the converging futures of systems biology and membrane biophysics, invoking the need to include physical variables such as location and geometry in the study of cellular membranes. WIREs Syst Biol Med 2017, 9:e1386. doi: 10.1002/wsbm.1386 For further resources related to this article, please visit the WIREs website.
Topics: Animals; Biophysical Phenomena; Cell Membrane; Humans; Signal Transduction; Systems Biology
PubMed: 28475297
DOI: 10.1002/wsbm.1386 -
BMC Plant Biology Jan 2021Cauliflower (Brassica oleracea L. var. botrytis) inflorescences are composed mainly of meristematic tissue, which has a high cellular proliferation. This considerable... (Comparative Study)
Comparative Study
BACKGROUND
Cauliflower (Brassica oleracea L. var. botrytis) inflorescences are composed mainly of meristematic tissue, which has a high cellular proliferation. This considerable cellular density makes the inflorescence an organ with a large proportion of membranes. However, little is known about the specific role of the lipid and protein composition of the plasma membrane present in this organ.
RESULTS
In this work, we analyzed the lipids and proteins present in plasma membrane from two different stages of development of cauliflower inflorescence and compared them with leaf plasma membrane. For this purpose, plasma membrane vesicles were obtained by centrifugation for each sample and the vesicular diameter and osmotic permeability (Pf) were analyzed by dynamic light scattering and the stopped-flow technique, respectively. In addition, fatty acids and sterols were analyzed by gas chromatography and HPLC. The protein composition of the inflorescences and leaves was characterized by HPLC-ESI-QTOF-MS and the data obtained were compared with Brassicaceae proteins present in the UniProt database in relation to the presence of aquaporins determined by western blot analysis. The highest Pf value was found in 90 day inflorescences-derived plasma membrane vesicles (61.4 ± 4.14 μms). For sterols and fatty acids, the concentrations varied according to the organ of origin. The protein profile revealed the presence of aquaporins from the PIP1 and PIP2 subfamilies in both inflorescences and leaves.
CONCLUSION
This study shows that the composition of the sterols, the degree of unsaturation of the fatty acids, and the proteins present in the membranes analyzed give them high functionality for water passage. This represents an important addition to the limited information available in this field.
Topics: Aquaporins; Brassica; Cell Membrane; Crops, Agricultural; Flowers; Membrane Lipids; Meristem; Osmosis; Permeability; Plant Leaves; Plant Proteins; Transport Vesicles; Water
PubMed: 33413105
DOI: 10.1186/s12870-020-02778-6 -
The Journal of Cell Biology Feb 2015Biological membranes segregate into specialized functional domains of distinct composition, which can persist for the entire life of the cell. How separation of their... (Review)
Review
Biological membranes segregate into specialized functional domains of distinct composition, which can persist for the entire life of the cell. How separation of their lipid and (glyco)protein components is generated and maintained is not well understood, but the existence of diffusional barriers has been proposed. Remarkably, the physical nature of such barriers and the manner whereby they impede the free diffusion of molecules in the plane of the membrane has rarely been studied in depth. Moreover, alternative mechanisms capable of generating membrane inhomogeneity are often disregarded. Here we describe prototypical biological systems where membrane segregation has been amply documented and discuss the role of diffusional barriers and other processes in the generation and maintenance of their structural and functional compartmentalization.
Topics: Animals; Cell Membrane; Cell Membrane Structures; Cytokinesis; Diffusion; Humans; Membrane Lipids; Membrane Proteins; Protein Transport
PubMed: 25646084
DOI: 10.1083/jcb.201410071 -
Cells Apr 2020Proteins associated with the yeast plasma membrane often accumulate asymmetrically within the plane of the membrane. Asymmetric accumulation is thought to underlie... (Review)
Review
Proteins associated with the yeast plasma membrane often accumulate asymmetrically within the plane of the membrane. Asymmetric accumulation is thought to underlie diverse processes, including polarized growth, stress sensing, and aging. Here, we review our evolving understanding of how cells achieve asymmetric distributions of membrane proteins despite the anticipated dissipative effects of diffusion, and highlight recent findings suggesting that differential diffusion is exploited to create, rather than dissipate, asymmetry. We also highlight open questions about diffusion in yeast plasma membranes that remain unsolved.
Topics: Cell Membrane; Cell Polarity; Diffusion; Membrane Proteins; Protein Transport; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins
PubMed: 32365827
DOI: 10.3390/cells9051113 -
Physiology (Bethesda, Md.) Nov 2015Plasma membrane repair is a conserved cellular response mediating active resealing of membrane disruptions to maintain homeostasis and prevent cell death and progression... (Review)
Review
Plasma membrane repair is a conserved cellular response mediating active resealing of membrane disruptions to maintain homeostasis and prevent cell death and progression of multiple diseases. Cell membrane repair repurposes mechanisms from various cellular functions, including vesicle trafficking, exocytosis, and endocytosis, to mend the broken membrane. Recent studies increased our understanding of membrane repair by establishing the molecular machinery contributing to membrane resealing. Here, we review some of the key proteins linked to cell membrane repair.
Topics: Animals; Cell Membrane; Homeostasis; Humans; Membrane Proteins; Regeneration; Signal Transduction
PubMed: 26525343
DOI: 10.1152/physiol.00019.2015 -
PloS One 2017The cholesterol content of membranes plays an important role in organizing membranes for signal transduction and protein trafficking as well as in modulating the...
The cholesterol content of membranes plays an important role in organizing membranes for signal transduction and protein trafficking as well as in modulating the biophysical properties of membranes. While the properties of model or isolated membranes have been extensively studied, there has been little evaluation of internal membranes in living cells. Here, we use a Nile Red based probe, NR12S, and ratiometric live cell imaging, to analyze the membrane order of the plasma membrane and endocytic recycling compartment. We find that after a brief incubation to allow endocytosis, NR12S is distributed between the plasma membrane and the endocytic recycling compartment. The NR12S reports that the endocytic recycling compartment is more highly ordered than the plasma membrane. We also find that the plasma membrane and the endocytic recycling compartment are differentially affected by altering cellular cholesterol levels. The membrane order of the plasma membrane, but not the endocytic recycling compartment, is altered significantly when cellular cholesterol content is increased or decreased by 20%. These results demonstrate that changes in cellular cholesterol differentially alter membrane order within different organelles.
Topics: Animals; Cell Compartmentation; Cell Membrane; Endocytosis
PubMed: 29125865
DOI: 10.1371/journal.pone.0188041 -
International Journal of Biological... 2020Phosphoinositides are membrane lipids generated by phosphorylation on the inositol head group of phosphatidylinositol. By specifically distributed to distinct... (Review)
Review
Phosphoinositides are membrane lipids generated by phosphorylation on the inositol head group of phosphatidylinositol. By specifically distributed to distinct subcellular membrane locations, different phosphoinositide species play diverse roles in modulating membrane trafficking. Among the seven known phosphoinositide species, phosphatidylinositol 4,5-bisphosphate (PI4,5P) is the one species most abundant at the plasma membrane. Thus, the PI4,5P function in membrane trafficking is first identified in controlling plasma membrane dynamic-related events including endocytosis and exocytosis. However, recent studies indicate that PI4,5P is also critical in many other membrane trafficking events such as endosomal trafficking, hydrolases sorting to lysosomes, autophagy initiation, and autophagic lysosome reformation. These findings suggest that the role of PI4,5P in membrane trafficking is far beyond just plasma membrane. This review will provide a concise synopsis of how PI4,5P functions in multiple membrane trafficking events. PI4,5P, the enzymes responsible for PI4,5P production at specific subcellular locations, and distinct PI4,5P effector proteins compose a regulation network to control the specific membrane trafficking events.
Topics: Cell Membrane; Cell Movement; Endocytosis; Phosphatidylinositol 4,5-Diphosphate; Phosphatidylinositols
PubMed: 33061794
DOI: 10.7150/ijbs.49665 -
PloS One 2022Caveolae are plasma membrane invaginations that play important roles in both endocytosis and membrane tension buffering. Typical caveolae have invaginated structures...
Caveolae are plasma membrane invaginations that play important roles in both endocytosis and membrane tension buffering. Typical caveolae have invaginated structures with a high-density caveolin assembly. Membrane sculpting proteins, including PACSIN2 and EHD2, are involved in caveolar biogenesis. PACSIN2 is an F-BAR domain-containing protein with a membrane sculpting ability that is essential for caveolar shaping. EHD2 is also localized at caveolae and involved in their stability. However, the spatial relationship between PACSIN2, EHD2, and caveolin has not yet been investigated. We observed the single-molecule localizations of PACSIN2 and EHD2 relative to caveolin-1 in three-dimensional space. The single-molecule localizations were grouped by their proximity localizations into the geometric structures of blobs. In caveolin-1 blobs, PACSIN2, EHD2, and caveolin-1 had overlapped spatial localizations. Interestingly, the mean centroid of the PACSIN2 F-BAR domain at the caveolin-1 blobs was closer to the plasma membrane than those of EHD2 and caveolin-1, suggesting that PACSIN2 is involved in connecting caveolae to the plasma membrane. Most of the blobs with volumes typical of caveolae had PACSIN2 and EHD2, in contrast to those with smaller volumes. Therefore, PACSIN2 and EHD2 are apparently localized at typically sized caveolae.
Topics: Adaptor Proteins, Signal Transducing; Caveolae; Caveolin 1; Cell Membrane; Endocytosis; Membrane Proteins
PubMed: 35834519
DOI: 10.1371/journal.pone.0271003