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Biochimica Et Biophysica Acta.... Apr 2022The plasma membrane (PM) is a highly heterogenous structure intertwined with the cortical actin cytoskeleton and extracellular matrix. This complex architecture makes it... (Review)
Review
The plasma membrane (PM) is a highly heterogenous structure intertwined with the cortical actin cytoskeleton and extracellular matrix. This complex architecture makes it difficult to study the processes taking place at the PM. Model membrane systems that are simple mimics of the PM overcome this bottleneck and allow us to study the biophysical principles underlying the processes at the PM. Among them, cell-derived giant plasma membrane vesicles (GPMVs) are considered the most physiologically relevant system, retaining the compositional complexity of the PM to a large extent. GPMVs have become a key tool in membrane research in the last few years. In this review, I will provide a brief overview of this system, summarize recent applications and discuss the limitations.
Topics: Actin Cytoskeleton; Cell Membrane; Drug Carriers; Lipidomics; Membrane Proteins; Unilamellar Liposomes
PubMed: 34990591
DOI: 10.1016/j.bbamem.2021.183857 -
International Journal of Molecular... Oct 2021The plasma membrane protects the eukaryotic cell from its surroundings and is essential for cell viability; thus, it is crucial that membrane disruptions are repaired... (Review)
Review
The plasma membrane protects the eukaryotic cell from its surroundings and is essential for cell viability; thus, it is crucial that membrane disruptions are repaired quickly to prevent immediate dyshomeostasis and cell death. Accordingly, cells have developed efficient repair mechanisms to rapidly reseal ruptures and reestablish membrane integrity. The cortical actin cytoskeleton plays an instrumental role in both plasma membrane resealing and restructuring in response to damage. Actin directly aids membrane repair or indirectly assists auxiliary repair mechanisms. Studies investigating single-cell wound repair have often focused on the recruitment and activation of specialized repair machinery, despite the undeniable need for rapid and dynamic cortical actin modulation; thus, the role of the cortical actin cytoskeleton during wound repair has received limited attention. This review aims to provide a comprehensive overview of membrane repair mechanisms directly or indirectly involving cortical actin cytoskeletal remodeling.
Topics: Actin Cytoskeleton; Animals; Cell Membrane; Cell Physiological Phenomena; Humans; Single-Cell Analysis; Wound Healing
PubMed: 34639226
DOI: 10.3390/ijms221910886 -
Open Biology Oct 2018Repair of wounds to individual cells is crucial for organisms to survive daily physiological or environmental stresses, as well as pathogen assaults, which disrupt the... (Review)
Review
Repair of wounds to individual cells is crucial for organisms to survive daily physiological or environmental stresses, as well as pathogen assaults, which disrupt the plasma membrane. Sensing wounds, resealing membranes, closing wounds and remodelling plasma membrane/cortical cytoskeleton are four major steps that are essential to return cells to their pre-wounded states. This process relies on dynamic changes of the membrane/cytoskeleton that are indispensable for carrying out the repairs within tens of minutes. Studies from different cell wound repair models over the last two decades have revealed that the molecular mechanisms of single cell wound repair are very diverse and dependent on wound type, size, and/or species. Interestingly, different repair models have been shown to use similar proteins to achieve the same end result, albeit sometimes by distinctive mechanisms. Recent studies using cutting edge microscopy and molecular techniques are shedding new light on the molecular mechanisms during cellular wound repair. Here, we describe what is currently known about the mechanisms underlying this repair process. In addition, we discuss how the study of cellular wound repair-a powerful and inducible model-can contribute to our understanding of other fundamental biological processes such as cytokinesis, cell migration, cancer metastasis and human diseases.
Topics: Animals; Cell Membrane; Cytoskeleton; Humans; Models, Animal; Single-Cell Analysis; Wound Healing
PubMed: 30282661
DOI: 10.1098/rsob.180135 -
Plant Physiology Dec 2021Far from a homogeneous environment, biological membranes are highly structured with lipids and proteins segregating in domains of different sizes and dwell times. In... (Review)
Review
Far from a homogeneous environment, biological membranes are highly structured with lipids and proteins segregating in domains of different sizes and dwell times. In addition, membranes are highly dynamics especially in response to environmental stimuli. Understanding the impact of the nanoscale organization of membranes on cellular functions is an outstanding question. Plant channels and transporters are tightly regulated to ensure proper cell nutrition and signaling. Increasing evidence indicates that channel and transporter nano-organization within membranes plays an important role in these regulation mechanisms. Here, we review recent advances in the field of ion, water, but also hormone transport in plants, focusing on protein organization within plasma membrane nanodomains and its cellular and physiological impacts.
Topics: Biological Transport; Cell Membrane; Microscopy, Fluorescence; Plant Physiological Phenomena; Signal Transduction
PubMed: 35235669
DOI: 10.1093/plphys/kiab312 -
Annual Review of Physical Chemistry Apr 2021Lateral organization in the plane of the plasma membrane is an important driver of biological processes. The past dozen years have seen increasing experimental support... (Review)
Review
Lateral organization in the plane of the plasma membrane is an important driver of biological processes. The past dozen years have seen increasing experimental support for the notion that lipid organization plays an important role in modulating this heterogeneity. Various biophysical mechanisms rooted in the concept of liquid-liquid phase separation have been proposed to explain diverse experimental observations of heterogeneity in model and cell membranes with distinct but overlapping applicability. In this review, we focus on the evidence for and the consequences of the hypothesis that the plasma membrane is poised near an equilibrium miscibility critical point. Critical phenomena explain certain features of the heterogeneity observed in cells and model systems but also go beyond heterogeneity to predict other interesting phenomena, including responses to perturbations in membrane composition.
Topics: Cell Membrane; Eukaryotic Cells; Membrane Lipids; Membrane Microdomains; Membrane Proteins
PubMed: 33710910
DOI: 10.1146/annurev-physchem-090419-115951 -
Cold Spring Harbor Perspectives in... Oct 2018The primary site of Ras signal transduction is the plasma membrane (PM). On the PM, the ubiquitously expressed Ras isoforms, H-, N-, and K-Ras, spatially segregate to... (Review)
Review
The primary site of Ras signal transduction is the plasma membrane (PM). On the PM, the ubiquitously expressed Ras isoforms, H-, N-, and K-Ras, spatially segregate to nonoverlapping nanometer-sized domains, called nanoclusters, with further lateral segregation into nonoverlapping guanosine triphosphate (GTP)-bound and guanosine diphosphate (GDP)-bound nanoclusters. Effector binding and activation is restricted to GTP nanoclusters, rendering the underlying assembly mechanism essential to Ras signaling. Ras nanoclusters have distinct lipid compositions as a result of lipid-sorting specificity encoded in each Ras carboxy-terminal membrane anchor. The role of the G-domain in regulating anchor-membrane interactions is becoming clearer. Ras G-domains undergo significant conformational orientation changes on guanine nucleotide switch, leading to differential direct contacts between the G-domain and reorganization of the membrane anchor. Ras G-domains also contain weak dimer interfaces, resulting in homodimerization, which is an obligate step of nanoclustering. Modulating the formation of Ras dimers, the lipid composition of the PM or lateral dynamics of key PM phospholipids represent novel mechanisms whereby the extent of Ras nanoclustering can be regulated to tune the gain in Ras signaling circuits.
Topics: Cell Membrane; Genes, ras; Signal Transduction
PubMed: 29229665
DOI: 10.1101/cshperspect.a031831 -
Molecules (Basel, Switzerland) Aug 2020Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P) is a minor but ubiquitous component of the inner leaflet of the plasma membrane of eukaryotic cells. However, due to its... (Review)
Review
Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P) is a minor but ubiquitous component of the inner leaflet of the plasma membrane of eukaryotic cells. However, due to its particular complex biophysical properties, it stands out from its neighboring lipids as one of the most important regulators of membrane-associated signaling events. Despite its very low steady-state concentration, PI(4,5)P is able to engage in a multitude of simultaneous cellular functions that are temporally and spatially regulated through the presence of localized transient pools of PI(4,5)P in the membrane. These pools are crucial for the recruitment, activation, and organization of signaling proteins and consequent regulation of downstream signaling. The present review showcases some of the most important PI(4,5)P2 molecular and biophysical properties as well as their impact on its membrane dynamics, lateral organization, and interactions with other biochemical partners.
Topics: Animals; Cell Membrane; Humans; Phosphatidylinositol 4,5-Diphosphate; Second Messenger Systems
PubMed: 32858905
DOI: 10.3390/molecules25173885 -
Frontiers in Immunology 2021Plasma membrane provides a biophysical and biochemical platform for immune cells to trigger signaling cascades and immune responses against attacks from foreign... (Review)
Review
Plasma membrane provides a biophysical and biochemical platform for immune cells to trigger signaling cascades and immune responses against attacks from foreign pathogens or tumor cells. Mounting evidence suggests that the biophysical-chemical properties of this platform, including complex compositions of lipids and cholesterols, membrane tension, and electrical potential, could cooperatively regulate the immune receptor functions. However, the molecular mechanism is still unclear because of the tremendous compositional complexity and spatio-temporal dynamics of the plasma membrane. Here, we review the recent significant progress of dynamical regulation of plasma membrane on immune receptors, including T cell receptor, B cell receptor, Fc receptor, and other important immune receptors, to proceed mechano-chemical sensing and transmembrane signal transduction. We also discuss how biophysical-chemical cues couple together to dynamically tune the receptor's structural conformation or orientation, distribution, and organization, thereby possibly impacting their ligand binding and related signal transduction. Moreover, we propose that electrical potential could potentially induce the biophysical-chemical coupling change, such as lipid distribution and membrane tension, to inevitably regulate immune receptor activation.
Topics: Animals; Binding Sites; Cell Membrane; Chemical Phenomena; Electrophysiological Phenomena; Humans; Mechanical Phenomena; Membrane Lipids; Protein Binding; Receptors, Immunologic; Signal Transduction
PubMed: 33679752
DOI: 10.3389/fimmu.2021.613185 -
Cell May 2019Over the last several decades, an impressive array of advanced microscopic and analytical tools, such as single-particle tracking and nanoscopic fluorescence correlation... (Review)
Review
Over the last several decades, an impressive array of advanced microscopic and analytical tools, such as single-particle tracking and nanoscopic fluorescence correlation spectroscopy, has been applied to characterize the lateral organization and mobility of components in the plasma membrane. Such analysis can tell researchers about the local dynamic composition and structure of membranes and is important for predicting the outcome of membrane-based reactions. However, owing to the unresolved complexity of the membrane and the structures peripheral to it, identification of the detailed molecular origin of the interactions that regulate the organization and mobility of the membrane has not proceeded quickly. This Perspective presents an overview of how cell-surface structure may give rise to the types of lateral mobility that are observed and some potentially fruitful future directions to elucidate the architecture of these structures in more molecular detail.
Topics: Cell Membrane; Lipid Bilayers; Membrane Lipids; Membrane Microdomains; Membrane Proteins
PubMed: 31051105
DOI: 10.1016/j.cell.2019.04.018 -
Trends in Plant Science Apr 2017The endoplasmic reticulum (ER) acts as a superhighway with multiple sideroads that connects the different membrane compartments including the ER to the plasma membrane... (Review)
Review
The endoplasmic reticulum (ER) acts as a superhighway with multiple sideroads that connects the different membrane compartments including the ER to the plasma membrane (PM). ER-PM contact sites (EPCSs) are a common feature in eukaryotic organisms, but have not been studied well in plants owing to the lack of molecular markers and to the difficulty in resolving the EPCS structure using conventional microscopy. Recently, however, plant protein complexes required for linking the ER and PM have been identified. This is a further step towards understanding the structure and function of plant EPCSs. We highlight some recent studies in this field and suggest several hypotheses that relate to the possible function of EPCSs in plants.
Topics: Cell Membrane; Endoplasmic Reticulum; Membrane Proteins; Plant Proteins
PubMed: 27955928
DOI: 10.1016/j.tplants.2016.11.008