scholarly journals Repair of injured plasma membrane by rapid Ca2+-dependent endocytosis

2008 ◽  
Vol 180 (5) ◽  
pp. 905-914 ◽  
Author(s):  
Vincent Idone ◽  
Christina Tam ◽  
John W. Goss ◽  
Derek Toomre ◽  
Marc Pypaert ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Immune System ◽  
Repair Process ◽  
Bacterial Toxin ◽  
Rapid Repair ◽  
Streptolysin O ◽  
Membrane Resealing ◽  
Pore Forming Proteins ◽  
Insight Into ◽  
Microbial Toxins

Ca2+ influx through plasma membrane lesions triggers a rapid repair process that was previously shown to require the exocytosis of lysosomal organelles (Reddy, A., E. Caler, and N. Andrews. 2001. Cell. 106:157–169). However, how exocytosis leads to membrane resealing has remained obscure, particularly for stable lesions caused by pore-forming proteins. In this study, we show that Ca2+-dependent resealing after permeabilization with the bacterial toxin streptolysin O (SLO) requires endocytosis via a novel pathway that removes SLO-containing pores from the plasma membrane. We also find that endocytosis is similarly required to repair lesions formed in mechanically wounded cells. Inhibition of lesion endocytosis (by sterol depletion) inhibits repair, whereas enhancement of endocytosis through disruption of the actin cytoskeleton facilitates resealing. Thus, endocytosis promotes wound resealing by removing lesions from the plasma membrane. These findings provide an important new insight into how cells protect themselves not only from mechanical injury but also from microbial toxins and pore-forming proteins produced by the immune system.

scholarly journals Molecular architecture of the endocytic TPLATE complex

2021 ◽  
Vol 7 (9) ◽  
pp. eabe7999
Author(s):  
Klaas Yperman ◽  
Jie Wang ◽  
Dominique Eeckhout ◽  
Joanna Winkler ◽  
Lam Dai Vu ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Structural Approach ◽  
Eukaryotic Cells ◽  
Molecular Architecture ◽  
Membrane Proteome ◽  
Complex Assembly ◽  
Membrane Interaction ◽  
Structural Insight ◽  
Fresh Insight ◽  
Insight Into

Eukaryotic cells rely on endocytosis to regulate their plasma membrane proteome and lipidome. Most eukaryotic groups, except fungi and animals, have retained the evolutionary ancient TSET complex as an endocytic regulator. Unlike other coatomer complexes, structural insight into TSET is lacking. Here, we reveal the molecular architecture of plant TSET [TPLATE complex (TPC)] using an integrative structural approach. We identify crucial roles for specific TSET subunits in complex assembly and membrane interaction. Our data therefore generate fresh insight into the differences between the hexameric TSET in Dictyostelium and the octameric TPC in plants. Structural elucidation of this ancient adaptor complex represents the missing piece in the coatomer puzzle and vastly advances our functional as well as evolutionary insight into the process of endocytosis.

Integrity of the dissociated adult cardiac myocyte: gap junction tearing and the mechanism of plasma membrane resealing

1990 ◽  
Vol 11 (2) ◽  
pp. 154-166 ◽  
Author(s):  
N. J. Severs ◽  
A. M. Slade ◽  
T. Powell ◽  
V. W. Twist ◽  
C. R. Green
Keyword(s):  
Plasma Membrane ◽  
Gap Junction ◽  
Cardiac Myocyte ◽  
Membrane Resealing

scholarly journals Cell wound repair in Drosophila occurs through three distinct phases of membrane and cytoskeletal remodeling

2011 ◽  
Vol 193 (3) ◽  
pp. 455-464 ◽  
Author(s):  
Maria Teresa Abreu-Blanco ◽  
Jeffrey M. Verboon ◽  
Susan M. Parkhurst
Keyword(s):  
Cell Death ◽  
Plasma Membrane ◽  
Single Cell ◽  
Wound Repair ◽  
Single Cells ◽  
Repair Process ◽  
Wound Edge ◽  
Cytoskeletal Remodeling ◽  
Tissue Integrity ◽  
E Cadherin

When single cells or tissues are injured, the wound must be repaired quickly in order to prevent cell death, loss of tissue integrity, and invasion by microorganisms. We describe Drosophila as a genetically tractable model to dissect the mechanisms of single-cell wound repair. By analyzing the expression and the effects of perturbations of actin, myosin, microtubules, E-cadherin, and the plasma membrane, we define three distinct phases in the repair process—expansion, contraction, and closure—and identify specific components required during each phase. Specifically, plasma membrane mobilization and assembly of a contractile actomyosin ring are required for this process. In addition, E-cadherin accumulates at the wound edge, and wound expansion is excessive in E-cadherin mutants, suggesting a role for E-cadherin in anchoring the actomyosin ring to the plasma membrane. Our results show that single-cell wound repair requires specific spatial and temporal cytoskeleton responses with distinct components and mechanisms required at different stages of the process.

Soluble proteins as modulators of the exocytotic reaction of permeabilised rat mast cells

1989 ◽  
Vol 94 (3) ◽  
pp. 585-591
Author(s):  
A. Koffer ◽  
B.D. Gomperts
Keyword(s):  
Plasma Membrane ◽  
Mast Cells ◽  
Soluble Proteins ◽  
The Other ◽  
Guanine Nucleotide ◽  
Cytoplasmic Proteins ◽  
Streptolysin O ◽  
Two Factors ◽  
Rat Mast Cells

This study addresses the question of the role of cytoplasmic proteins in exocytosis from permeabilised rat mast cells. We have used two different methods of cell permeabilisation (ATP4- and streptolysin O) to regulate the size of the plasma membrane lesions, and thus to dictate the rate and extent of efflux of the cytosolic proteins, and compared the secretory response of the two preparations. We report evidence for the existence of two factors present in the cytosol, which affect the exocytotic mechanism in opposing manners. One of these is required for the maintenance of cell responsiveness; it is retained for more than 120 min by ATP4- -permeabilised cells but lost within 60 min from cells permeabilised by streptolysin O. The other factor, which leaks immediately from cells treated from streptolysin O, but only gradually from cells treated with ATP4-, has the effect of suppressing the affinity for both Ca2+ and guanine nucleotide in the exocytotic reaction.

scholarly journals Palmitoylated Cysteines in Chikungunya Virus nsP1 Are Critical for Targeting to Cholesterol-Rich Plasma Membrane Microdomains with Functional Consequences for Viral Genome Replication

2020 ◽  
Vol 94 (10) ◽  
Author(s):  
William Bakhache ◽  
Aymeric Neyret ◽  
Eric Bernard ◽  
Andres Merits ◽  
Laurence Briant
Keyword(s):  
Plasma Membrane ◽  
Lipid Bilayers ◽  
Functional Role ◽  
Membrane Microdomains ◽  
Genome Replication ◽  
Functional Importance ◽  
Late Endosomes ◽  
Plasma Membrane Microdomains ◽  
Insight Into

ABSTRACT In mammalian cells, alphavirus replication complexes are anchored to the plasma membrane. This interaction with lipid bilayers is mediated through the viral methyl/guanylyltransferase nsP1 and reinforced by palmitoylation of cysteine residue(s) in the C-terminal region of this protein. Lipid content of membranes supporting nsP1 anchoring remains poorly studied. Here, we explore the membrane binding capacity of nsP1 with regard to cholesterol. Using the medically important chikungunya virus (CHIKV) as a model, we report that nsP1 cosegregates with cholesterol-rich detergent-resistant membrane microdomains (DRMs), also called lipid rafts. In search for the critical factor for cholesterol partitioning, we identify nsP1 palmitoylated cysteines as major players in this process. In cells infected with CHIKV or transfected with CHIKV trans-replicase plasmids, nsP1, together with the other nonstructural proteins, are detected in DRMs. While the functional importance of CHIKV nsP1 preference for cholesterol-rich membrane domains remains to be determined, we observed that U18666A- and imipramine-induced sequestration of cholesterol in late endosomes redirected nsP1 to these compartments and simultaneously dramatically decreased CHIKV genome replication. A parallel study of Sindbis virus (SINV) revealed that nsP1 from this divergent alphavirus displays a low affinity for cholesterol and only moderately segregates with DRMs. Behaviors of CHIKV and SINV with regard to cholesterol, therefore, match with the previously reported differences in the requirement for nsP1 palmitoylation, which is dispensable for SINV but strictly required for CHIKV replication. Altogether, this study highlights the functional importance of nsP1 segregation with DRMs and provides new insight into the functional role of nsP1 palmitoylated cysteines during alphavirus replication. IMPORTANCE Functional alphavirus replication complexes are anchored to the host cell membranes through the interaction of nsP1 with the lipid bilayers. In this work, we investigate the importance of cholesterol for such an association. We show that nsP1 has affinity for cholesterol-rich membrane microdomains formed at the plasma membrane and identify conserved palmitoylated cysteine(s) in nsP1 as the key determinant for cholesterol affinity. We demonstrate that drug-induced cholesterol sequestration in late endosomes not only redirects nsP1 to this compartment but also dramatically decreases genome replication, suggesting the functional importance of nsP1 targeting to cholesterol-rich plasma membrane microdomains. Finally, we show evidence that nsP1 from chikungunya and Sindbis viruses displays different sensitivity to cholesterol sequestering agents that parallel with their difference in the requirement for nsP1 palmitoylation for replication. This research, therefore, gives new insight into the functional role of palmitoylated cysteines in nsP1 for the assembly of functional alphavirus replication complexes in their mammalian host.

scholarly journals Insights into Sensing of Murine Retroviruses

Viruses ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 836
Author(s):  
Eileen A. Moran ◽  
Susan R. Ross
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Nucleic Acid ◽  
Adaptive Immunity ◽  
Innate Immune System ◽  
Innate Immune ◽  
Genetic Tool ◽  
Causes Of Disease ◽  
Retrovirus Infection ◽  
Insight Into

Retroviruses are major causes of disease in animals and human. Better understanding of the initial host immune response to these viruses could provide insight into how to limit infection. Mouse retroviruses that are endemic in their hosts provide an important genetic tool to dissect the different arms of the innate immune system that recognize retroviruses as foreign. Here, we review what is known about the major branches of the innate immune system that respond to mouse retrovirus infection, Toll-like receptors and nucleic acid sensors, and discuss the importance of these responses in activating adaptive immunity and controlling infection.

scholarly journals Loss of calpains-1 and -2 prevents repair of plasma membrane scrape injuries, but not small pores, and induces a severe muscular dystrophy

2020 ◽  
Vol 318 (6) ◽  
pp. C1226-C1237
Author(s):  
Ann-Katrin Piper ◽  
Reece A. Sophocleous ◽  
Samuel E. Ross ◽  
Frances J. Evesson ◽  
Omar Saleh ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Muscular Dystrophy ◽  
Disease Genes ◽  
Spastic Paraplegia ◽  
Membrane Repair ◽  
Membrane Injury ◽  
Streptolysin O ◽  
Calpain 2 ◽  
Cytoskeletal Networks

The ubiquitous calpains, calpain-1 and -2, play important roles in Ca2+-dependent membrane repair. Mechanically active tissues like skeletal muscle are particularly reliant on mechanisms to repair and remodel membrane injury, such as those caused by eccentric damage. We demonstrate that calpain-1 and -2 are master effectors of Ca2+-dependent repair of mechanical plasma membrane scrape injuries, although they are dispensable for repair/removal of small wounds caused by pore-forming agents. Using CRISPR gene-edited human embryonic kidney 293 (HEK293) cell lines, we established that loss of both calpains-1 and -2 ( CAPNS1−/−) virtually ablates Ca2+-dependent repair of mechanical scrape injuries but does not affect injury or recovery from perforation by streptolysin-O or saponin. In contrast, cells with targeted knockout of either calpain-1 ( CAPN1−/−) or -2 ( CAPN2−/−) show near-normal repair of mechanical injuries, inferring that both calpain-1 and calpain-2 are equally capable of conducting the cascade of proteolytic cleavage events to reseal a membrane injury, including that of the known membrane repair agent dysferlin. A severe muscular dystrophy in a murine model with skeletal muscle knockout of Capns1 highlights vital roles for calpain-1 and/or -2 for health and viability of skeletal muscles not compensated for by calpain-3 ( CAPN3). We propose that the dystrophic phenotype relates to loss of maintenance of plasma membrane/cytoskeletal networks by calpains-1 and -2 in response to directed and dysfunctional Ca2+-signaling, pathways hyperstimulated in the context of membrane injury. With CAPN1 variants associated with spastic paraplegia, a severe dystrophy observed with muscle-specific loss of calpain-1 and -2 activity identifies CAPN2 and CAPNS1 as plausible candidate neuromuscular disease genes.

scholarly journals Naturally occurring and tumor-associated variants of RNF167 promote lysosomal exocytosis and plasma membrane resealing

2020 ◽  
Vol 133 (11) ◽  
pp. jcs239335 ◽  
Author(s):  
Sreeja V. Nair ◽  
Nikhil Dev Narendradev ◽  
Rithwik P. Nambiar ◽  
Rakesh Kumar ◽  
Srinivasa M. Srinivasula
Keyword(s):  
Plasma Membrane ◽  
Naturally Occurring ◽  
Membrane Resealing

scholarly journals Multiple poloxamers increase plasma membrane repair capacity in muscle and nonmuscle cells

2020 ◽  
Vol 318 (2) ◽  
pp. C253-C262 ◽  
Author(s):  
Thomas A. Kwiatkowski ◽  
Aubrey L. Rose ◽  
Rachel Jung ◽  
Ana Capati ◽  
Diana Hallak ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Muscular Dystrophy ◽  
Ethylene Oxide ◽  
Propylene Oxide ◽  
Hek293 Cells ◽  
Mdx Mouse ◽  
Repair Capacity ◽  
Poly Ethylene Oxide ◽  
Membrane Resealing ◽  
Poly Ethylene

Various previous studies established that the amphiphilic tri-block copolymer known as poloxamer 188 (P188) or Pluronic-F68 can stabilize the plasma membrane following a variety of injuries to multiple mammalian cell types. This characteristic led to proposals for the use of P188 as a therapeutic treatment for various disease states, including muscular dystrophy. Previous studies suggest that P188 increases plasma membrane integrity by resealing plasma membrane disruptions through its affinity for the hydrophobic lipid chains on the lipid bilayer. P188 is one of a large family of copolymers that share the same basic tri-block structure consisting of a middle hydrophobic propylene oxide segment flanked by two hydrophilic ethylene oxide moieties [poly(ethylene oxide)80-poly(propylene oxide)27-poly(ethylene oxide)80]. Despite the similarities of P188 to the other poloxamers in this chemical family, there has been little investigation into the membrane-resealing properties of these other poloxamers. In this study we assessed the resealing properties of poloxamers P181, P124, P182, P234, P108, P407, and P338 on human embryonic kidney 293 (HEK293) cells and isolated muscle from the mdx mouse model of Duchenne muscular dystrophy. Cell membrane injuries from glass bead wounding and multiphoton laser injury show that the majority of poloxamers in our panel improved the plasma membrane resealing of both HEK293 cells and dystrophic muscle fibers. These findings indicate that many tri-block copolymers share characteristics that can increase plasma membrane resealing and that identification of these shared characteristics could help guide design of future therapeutic approaches.

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