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Cellular and Molecular Life Sciences :... Apr 2019Pore-forming toxins (PFTs) are key virulence determinants produced and secreted by a variety of human bacterial pathogens. They disrupt the plasma membrane (PM) by... (Review)
Review
Pore-forming toxins (PFTs) are key virulence determinants produced and secreted by a variety of human bacterial pathogens. They disrupt the plasma membrane (PM) by generating stable protein pores, which allow uncontrolled exchanges between the extracellular and intracellular milieus, dramatically disturbing cellular homeostasis. In recent years, many advances were made regarding the characterization of conserved repair mechanisms that allow eukaryotic cells to recover from mechanical disruption of the PM membrane. However, the specificities of the cell recovery pathways that protect host cells against PFT-induced damage remain remarkably elusive. During bacterial infections, the coordinated action of such cell recovery processes defines the outcome of infected cells and is, thus, critical for our understanding of bacterial pathogenesis. Here, we review the cellular pathways reported to be involved in the response to bacterial PFTs and discuss their impact in single-cell recovery and infection.
Topics: Actomyosin; Autophagosomes; Bacteria; Bacterial Toxins; Cell Membrane; Cytoskeleton; Exocytosis; Humans; Lysosomes; Phagocytosis
PubMed: 30591958
DOI: 10.1007/s00018-018-2992-8 -
Methods in Molecular Biology (Clifton,... 2023Plasma membrane injury activates membrane trafficking and remodeling events that are required for the injured membrane to repair. With the rapidity of the membrane...
Plasma membrane injury activates membrane trafficking and remodeling events that are required for the injured membrane to repair. With the rapidity of the membrane repair process, the repair response needs to be monitored at high temporal and spatial resolution. In this chapter, we describe the use of live cell optical imaging approaches to monitor injury-triggered bulk and individual vesicle endocytosis. Use of these approaches allows quantitatively assessment of the rate of retrieval of the injured plasma membrane by bulk endocytosis as well as by endocytosis of individual caveolae following plasma membrane injury.
Topics: Endocytosis; Cell Membrane; Synaptic Vesicles
PubMed: 36401047
DOI: 10.1007/978-1-0716-2772-3_27 -
Molecular Biology of the Cell Feb 2020Eisosomes are membrane furrows at the cell surface of yeast that have been shown to function in two seemingly distinct pathways, membrane stress response and regulation...
Eisosomes are membrane furrows at the cell surface of yeast that have been shown to function in two seemingly distinct pathways, membrane stress response and regulation of nutrient transporters. We found that many stress conditions affect both of these pathways by changing plasma membrane tension and thus the morphology and composition of eisosomes. For example, alkaline stress causes swelling of the cell and an endocytic response, which together increase membrane tension, thereby flattening the eisosomes. The flattened eisosomes affect membrane stress pathways and release nutrient transporters, which aids in their down-regulation. In contrast, glucose starvation or hyperosmotic shock causes cell shrinking, which results in membrane slack and the deepening of eisosomes. Deepened eisosomes are able to trap nutrient transporters and protect them from rapid endocytosis. Therefore, eisosomes seem to coordinate the regulation of both membrane tension and nutrient transporter stability.
Topics: Biological Transport; Cell Membrane; Cytoskeletal Proteins; Gene Expression Regulation, Fungal; Glucose; Nucleotide Transport Proteins; Osmotic Pressure; Phosphoproteins; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Sorbitol; Surface Tension
PubMed: 31851579
DOI: 10.1091/mbc.E19-04-0218 -
Plant Physiology Apr 2020Plasma membranes provide a highly selective environment for a large number of transmembrane and membrane-associated proteins. Whereas lateral movement of proteins in... (Review)
Review
Plasma membranes provide a highly selective environment for a large number of transmembrane and membrane-associated proteins. Whereas lateral movement of proteins in this lipid bilayer is possible, it is rather limited in turgid and cell wall-shielded plant cells. However, membrane-resident signaling processes occur on subsecond scales that cannot be explained by simple diffusion models. Accordingly, several receptors and other membrane-associated proteins are organized and functional in membrane nanodomains. Although the general presence of membrane nanodomains has become widely accepted as fact, fundamental functional aspects, the roles of individual lipid species and their interplay with proteins, and aspects of nanodomain maintenance and persistence remain poorly understood. Here, we review the current knowledge of nanodomain organization and function, with a particular focus on signaling processes involving proteins, lipids, and their interactions. Furthermore, we propose new and hypothetical aspects of plant membrane biology that we consider important for future research.
Topics: Cell Membrane; Membrane Microdomains; Models, Biological; Proteolipids; Signal Transduction
PubMed: 31857424
DOI: 10.1104/pp.19.01349 -
International Journal of Molecular... Aug 2020The composition and organization of the plasma membrane play important functional and regulatory roles in integrin signaling, which direct many physiological and... (Review)
Review
The composition and organization of the plasma membrane play important functional and regulatory roles in integrin signaling, which direct many physiological and pathological processes, such as development, wound healing, immunity, thrombosis, and cancer metastasis. Membranes are comprised of regions that are thick or thin owing to spontaneous partitioning of long-chain saturated lipids from short-chain polyunsaturated lipids into domains defined as ordered and liquid-disorder domains, respectively. Liquid-ordered domains are typically 100 nm in diameter and sometimes referred to as lipid rafts. We posit that integrin β senses membrane thickness and that mechanical force on the membrane regulates integrin activation through membrane thinning. This review examines what we know about the nature and mechanism of the interaction of integrins with the plasma membrane and its effects on regulating integrins and its binding partners.
Topics: Cell Adhesion; Cell Membrane; Focal Adhesions; Humans; Integrins; Membrane Lipids; Membrane Microdomains; Membrane Proteins; Protein Binding; Signal Transduction
PubMed: 32752284
DOI: 10.3390/ijms21155531 -
Small GTPases Apr 2017The plasma membrane is generally associated with underling actin cytoskeleton. When the plasma membrane detaches from actin filaments, it is expanded by the... (Review)
Review
The plasma membrane is generally associated with underling actin cytoskeleton. When the plasma membrane detaches from actin filaments, it is expanded by the intracellular pressure and the spherical membrane protrusion which lacks underlying actin cortex, termed bleb, is formed. Bleb is widely used for migration across species; however, the molecular mechanism underlying membrane blebbing remains largely unknown. Our recent study revealed that 2 small GTPases, Rnd3 and RhoA, are important regulators of membrane blebbing. In the expanding blebs, Rnd3 is recruited to the plasma membrane and inhibits RhoA activity by activating RhoGAP. On the other hand, RhoA is activated at the retracting membrane and removes Rnd3 from plasma membrane by the activity of ROCK (Rho-associated protein kinase). ROCK is also important for the rapid reassembly of actin cortex and retraction of membrane blebs by activating Ezrin. We propose that a Rnd3 and RhoA cycle underlies the core machinery of continuous membrane blebbing.
Topics: Actin Cytoskeleton; Animals; Cell Membrane; Humans; Monomeric GTP-Binding Proteins
PubMed: 27314434
DOI: 10.1080/21541248.2016.1199266 -
Current Opinion in Cell Biology Oct 2020The cell surface is a mechanobiological unit that encompasses the plasma membrane, its interacting proteins, and the complex underlying cytoskeleton. Recently, attention... (Review)
Review
The cell surface is a mechanobiological unit that encompasses the plasma membrane, its interacting proteins, and the complex underlying cytoskeleton. Recently, attention has been directed to the mechanics of the plasma membrane, and in particular membrane tension, which has been linked to diverse cellular processes such as cell migration and membrane trafficking. However, how tension across the plasma membrane is regulated and propagated is still not completely understood. Here, we review recent efforts to study the interplay between membrane tension and the cytoskeletal machinery and how they control cell form and function. We focus on factors that have been proposed to affect the propagation of membrane tension and as such could determine whether it can act as a global or local regulator of cell behavior. Finally, we discuss the limitations of the available tool kit as new approaches that reveal its dynamics in cells are needed to decipher how membrane tension regulates diverse cellular processes.
Topics: Animals; Biomechanical Phenomena; Biophysics; Cell Membrane; Cell Movement; Humans; Microtubules
PubMed: 32416466
DOI: 10.1016/j.ceb.2020.04.001 -
Biology of the Cell Aug 2021Deformability of the plasma membrane, the outermost surface of metazoan cells, allows cells to be dynamic, mobile and flexible. Factors that affect this deformability,... (Review)
Review
Deformability of the plasma membrane, the outermost surface of metazoan cells, allows cells to be dynamic, mobile and flexible. Factors that affect this deformability, such as tension on the membrane, can regulate a myriad of cellular functions, including membrane resealing, cell motility, polarisation, shape maintenance, membrane area control and endocytic vesicle trafficking. This review focuses on mechanoregulation of clathrin-mediated endocytosis (CME). We first delineate the origins of cell membrane tension and the factors that yield to its spatial and temporal fluctuations within cells. We then review the recent literature demonstrating that tension on the membrane is a fast-acting and reversible regulator of CME. Finally, we discuss tension-based regulation of endocytic clathrin coat formation during physiological processes.
Topics: Animals; Cell Membrane; Clathrin; Clathrin-Coated Vesicles; Endocytosis; Eukaryotic Cells; Exocytosis; Humans; Protein Transport; Transport Vesicles
PubMed: 33788963
DOI: 10.1111/boc.202000110 -
Microbiology and Molecular Biology... Nov 2020There is growing appreciation that the plasma membrane orchestrates a diverse array of functions by segregating different activities into specialized domains that vary... (Review)
Review
There is growing appreciation that the plasma membrane orchestrates a diverse array of functions by segregating different activities into specialized domains that vary in size, stability, and composition. Studies with the budding yeast have identified a novel type of plasma membrane domain known as the MCC (membrane compartment of Can1)/eisosomes that correspond to stable furrows in the plasma membrane. MCC/eisosomes maintain proteins at the cell surface, such as nutrient transporters like the Can1 arginine symporter, by protecting them from endocytosis and degradation. Recent studies from several fungal species are now revealing new functional roles for MCC/eisosomes that enable cells to respond to a wide range of stressors, including changes in membrane tension, nutrition, cell wall integrity, oxidation, and copper toxicity. The different MCC/eisosome functions are often intertwined through the roles of these domains in lipid homeostasis, which is important for proper plasma membrane architecture and cell signaling. Therefore, this review will emphasize the emerging models that explain how MCC/eisosomes act as hubs to coordinate cellular responses to stress. The importance of MCC/eisosomes is underscored by their roles in virulence for fungal pathogens of plants, animals, and humans, which also highlights the potential of these domains to act as novel therapeutic targets.
Topics: Amino Acid Transport Systems, Basic; Cell Membrane; Endocytosis; Fungi; Membrane Microdomains; Membrane Proteins; Morphogenesis; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Stress, Physiological; Virulence
PubMed: 32938742
DOI: 10.1128/MMBR.00063-19 -
FEBS Letters Jan 2015Phospholipid scramblase activity is involved in the collapse of phospholipid (PL) asymmetry at the plasma membrane leading to externalization of phosphatidylserine. This... (Review)
Review
Phospholipid scramblase activity is involved in the collapse of phospholipid (PL) asymmetry at the plasma membrane leading to externalization of phosphatidylserine. This activity is crucial for initiation of the blood coagulation cascade and for recognition/elimination of apoptotic cells by macrophages. Efforts to identify gene products associated with this activity led to the characterization of PL scramblase (PLSCR) and XKR family members which contribute to phosphatidylserine exposure in response to apoptotic stimuli. Meanwhile, TMEM16 family members were identified to externalize phosphatidylserine in response to elevated calcium in Scott syndrome platelets, which is critical for activation of the coagulation cascade. Herein, we report their mechanisms of gene regulation, molecular functions independent of their scrambling activity, and their potential roles in pathogenic conditions.
Topics: Animals; Apoptosis; Blood Coagulation Disorders; Blood Platelets; Cell Membrane; Humans; Phosphatidylserines; Phospholipid Transfer Proteins
PubMed: 25479087
DOI: 10.1016/j.febslet.2014.11.036