scholarly journals Mechanochemical feedback and control of endocytosis and membrane tension

2017 ◽  
Author(s):  
Joseph Jose Thottacherry ◽  
Anita Joanna Kosmalska ◽  
Alberto Elosegui-Artola ◽  
Susav Pradhan ◽  
Sumit Sharma ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Trafficking ◽  
Feedback Loop ◽  
Negative Feedback Loop ◽  
Dependent Manner ◽  
Homeostatic Regulation ◽  
Membrane Tension ◽  
Cellular Processes ◽  
Tightly Coupled ◽  
And Control

AbstractPlasma membrane tension is an important factor that regulates many key cellular processes. Membrane trafficking is tightly coupled to membrane tension and can modulate the latter by addition or removal of the membrane. However, the cellular pathway(s) involved in these processes are poorly understood. Here we find that, among a number of endocytic processes operating simultaneously at the cell surface, a dynamin and clathrin-independent pathway, the CLIC/GEEC (CG) pathway, is rapidly and specifically upregulated upon reduction of tension. On the other hand, inhibition of the CG pathway results in lower membrane tension, while up regulation significantly enhances membrane tension. We find that vinculin, a well-studied mechanotransducer, mediates the tension-dependent regulation of the CG pathway. Vinculin negatively regulates a key CG pathway regulator, GBF1, at the plasma membrane in a tension dependent manner. Thus, the CG pathway operates in a negative feedback loop with membrane tension which leads to a homeostatic regulation of membrane tension.

scholarly journals TOR complex 2 (TORC2) signaling and the ESCRT machinery cooperate in the protection of plasma membrane integrity in yeast

2020 ◽  
Vol 295 (34) ◽  
pp. 12028-12044
Author(s):  
Oliver Schmidt ◽  
Yannick Weyer ◽  
Simon Sprenger ◽  
Michael A. Widerin ◽  
Sebastian Eising ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Integrity ◽  
Homeostatic Regulation ◽  
Membrane Tension ◽  
Membrane Remodeling ◽  
Plasma Membrane Integrity ◽  
Endosomal Sorting ◽  
Escrt Machinery ◽  
Evolutionarily Conserved ◽  
Calcineurin Activity

The endosomal sorting complexes required for transport (ESCRT) mediate evolutionarily conserved membrane remodeling processes. Here, we used budding yeast (Saccharomyces cerevisiae) to explore how the ESCRT machinery contributes to plasma membrane (PM) homeostasis. We found that in response to reduced membrane tension and inhibition of TOR complex 2 (TORC2), ESCRT-III/Vps4 assemblies form at the PM and help maintain membrane integrity. In turn, the growth of ESCRT mutants strongly depended on TORC2-mediated homeostatic regulation of sphingolipid (SL) metabolism. This was caused by calcineurin-dependent dephosphorylation of Orm2, a repressor of SL biosynthesis. Calcineurin activity impaired Orm2 export from the endoplasmic reticulum (ER) and thereby hampered its subsequent endosome and Golgi-associated degradation (EGAD). The ensuing accumulation of Orm2 at the ER in ESCRT mutants necessitated TORC2 signaling through its downstream kinase Ypk1, which repressed Orm2 and prevented a detrimental imbalance of SL metabolism. Our findings reveal compensatory cross-talk between the ESCRT machinery, calcineurin/TORC2 signaling, and the EGAD pathway important for the regulation of SL biosynthesis and the maintenance of PM homeostasis.

scholarly journals Calcium-binding protein S100A6 interaction with VEGF receptors integrates signaling and trafficking pathways

2021 ◽  
Author(s):  
Sreenivasan Ponnambalam ◽  
Leyuan Bao ◽  
Gareth W Fearnley ◽  
Chi-Chuan Lin ◽  
Adam F Odell ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Trafficking ◽  
Calcium Binding ◽  
Mapk Pathway ◽  
Binding Protein ◽  
Calcium Binding Protein ◽  
Mitogen Activated Protein Kinase ◽  
Tyrosine Kinase Domain ◽  
Dependent Manner ◽  
Endothelial Cell Function

The mammalian endothelium which lines all blood vessels responds to soluble factors which control vascular development and sprouting. Endothelial cells bind to vascular endothelial growth factor A via two different receptor tyrosine kinases (VEGFR1, VEGFR2) which regulate such cellular responses. The integration of VEGFR signal transduction and membrane trafficking is not well understood. Here, we used a yeast-based membrane protein screen to identify VEGFR-interacting factor(s) which modulate endothelial cell function. By screening a human endothelial cDNA library, we identified a calcium-binding protein, S100A6, which can interact with either VEGFR. We found that S100A6 binds in a calcium-dependent manner to either VEGFR1 or VEGFR2. S100A6 binding was mapped to the VEGFR2 tyrosine kinase domain. Depletion of S100A6 impacts on VEGF-A-regulated signaling through the canonical mitogen-activated protein kinase (MAPK) pathway. Furthermore, S100A6 depletion caused contrasting effects on biosynthetic VEGFR delivery to the plasma membrane. Co-distribution of S100A6 and VEGFRs on tubular profiles suggest the presence of transport carriers that facilitate VEGFR trafficking. We propose a mechanism whereby S100A6 acts as a calcium regulated switch which facilitates biosynthetic VEGFR trafficking from the TGN-to-plasma membrane. VEGFR-S100A6 interactions thus enable integration of signaling and trafficking pathways in controlling the endothelial response to VEGF-A.

scholarly journals NODULE INCEPTION creates a long-distance negative feedback loop involved in homeostatic regulation of nodule organ production

2014 ◽  
Vol 111 (40) ◽  
pp. 14607-14612 ◽  
Author(s):  
Takashi Soyano ◽  
Hideki Hirakawa ◽  
Shusei Sato ◽  
Makoto Hayashi ◽  
Masayoshi Kawaguchi
Keyword(s):  
Negative Feedback ◽  
Feedback Loop ◽  
Negative Feedback Loop ◽  
Homeostatic Regulation ◽  
Long Distance

scholarly journals Membrane mechanics govern spatiotemporal heterogeneity of endocytic clathrin coat dynamics

2017 ◽  
Vol 28 (24) ◽  
pp. 3480-3488 ◽  
Author(s):  
N. M. Willy ◽  
J. P. Ferguson ◽  
S. D. Huber ◽  
S. P. Heidotting ◽  
E. Aygün ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Morphological Changes ◽  
Cell Types ◽  
Membrane Tension ◽  
Membrane Mechanics ◽  
Cellular Processes ◽  
Spatiotemporal Heterogeneity ◽  
Multicellular Organisms ◽  
Different Cell Types

Dynamics of endocytic clathrin-coated structures can be remarkably divergent across different cell types, cells within the same culture, or even distinct surfaces of the same cell. The origin of this astounding heterogeneity remains to be elucidated. Here we show that cellular processes associated with changes in effective plasma membrane tension induce significant spatiotemporal alterations in endocytic clathrin coat dynamics. Spatiotemporal heterogeneity of clathrin coat dynamics is also observed during morphological changes taking place within developing multicellular organisms. These findings suggest that tension gradients can lead to patterning and differentiation of tissues through mechanoregulation of clathrin-mediated endocytosis.

scholarly journals The mesoscale organization of syntaxin 1A and SNAP25 is determined by SNARE-SNARE-interactions

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Jasmin Mertins ◽  
Jérôme Finke ◽  
Ricarda Antonia Sies ◽  
Kerstin Rink ◽  
Jan Hasenauer ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Fusion ◽  
Secretory Pathway ◽  
Snare Proteins ◽  
Strong Interactions ◽  
Dependent Manner ◽  
Syntaxin 1A ◽  
Membrane Area ◽  
Cellular Processes ◽  
Domain Interactions

SNARE proteins have been described as the effectors of fusion events in the secretory pathway more than two decades ago. The strong interactions between SNARE-domains are clearly important in membrane fusion, but it is unclear whether they are involved in any other cellular processes. Here, we analyzed two classical SNARE proteins, syntaxin 1A and SNAP25. Although they are supposed to be engaged in tight complexes, we surprisingly find them largely segregated in the plasma membrane. Syntaxin 1A only occupies a small fraction of the plasma membrane area. Yet, we find it is able to redistribute the far more abundant SNAP25 on the mesoscale by gathering crowds of SNAP25 molecules onto syntaxin-clusters in a SNARE-domain dependent manner. Our data suggests that SNARE-domain interactions are not only involved in driving membrane fusion on the nanoscale, but also play an important role in controlling the general organization of proteins on the mesoscale. Further, we propose this mechanisms preserves active syntaxin 1A-SNAP25 complexes at the plasma membrane.

scholarly journals Septins suppress the release of vaccinia virus from infected cells

2018 ◽  
Vol 217 (8) ◽  
pp. 2911-2929 ◽  
Author(s):  
Julia Pfanzelter ◽  
Serge Mostowy ◽  
Michael Way
Keyword(s):  
Plasma Membrane ◽  
Vaccinia Virus ◽  
Membrane Trafficking ◽  
Live Cell Imaging ◽  
Actin Polymerization ◽  
Antiviral Effect ◽  
Cellular Processes ◽  
Viral Egress ◽  
Infected Cells ◽  
Cell Spread

Septins are conserved components of the cytoskeleton that play important roles in many fundamental cellular processes including division, migration, and membrane trafficking. Septins can also inhibit bacterial infection by forming cage-like structures around pathogens such as Shigella. We found that septins are recruited to vaccinia virus immediately after its fusion with the plasma membrane during viral egress. RNA interference–mediated depletion of septins increases virus release and cell-to-cell spread, as well as actin tail formation. Live cell imaging reveals that septins are displaced from the virus when it induces actin polymerization. Septin loss, however, depends on the recruitment of the SH2/SH3 adaptor Nck, but not the activity of the Arp2/3 complex. Moreover, it is the recruitment of dynamin by the third Nck SH3 domain that displaces septins from the virus in a formin-dependent fashion. Our study demonstrates that septins suppress vaccinia release by “entrapping” the virus at the plasma membrane. This antiviral effect is overcome by dynamin together with formin-mediated actin polymerization.

scholarly journals Rab coupling protein is selectively degraded by calpain in a Ca2+-dependent manner

2005 ◽  
Vol 389 (1) ◽  
pp. 223-231 ◽  
Author(s):  
Nicolas MARIE ◽  
Andrew J. LINDSAY ◽  
Mary W. McCAFFREY
Keyword(s):  
Plasma Membrane ◽  
Membrane Trafficking ◽  
Calpain Inhibitor ◽  
Dependent Manner ◽  
Interacting Proteins ◽  
Wild Type ◽  
A431 Cells ◽  
Calcium Dependent ◽  
Coupling Protein ◽  
Calpain Inhibitors

RCP (Rab coupling protein) belongs to the recently identified Rab11-FIPs (Rab11 family of interacting proteins). All the Rab-FIP members have the ability to bind Rab11 tightly via a Rab-binding domain located near their C-termini. RCP belongs to the class I Rab11-FIP subfamily, characterized by the presence of a conserved C2 domain near its N-terminus. The function of this protein in Rab11-dependent membrane trafficking remains to be fully understood. In the present study, we have identified three putative PEST (Pro, Glu, Ser/Thr-rich) sequences in RCP. PEST motifs play a role in targeting a protein for proteolytic degradation. We have demonstrated that RCP undergoes calcium-dependent degradation which can be prevented by specific calpain inhibitors. Using a mutant, lacking the three PEST sequences, RCPΔPEST, we demonstrated that they are necessary for the cleavage of RCP by calpains. When expressed in A431 cells, RCPΔPEST displays significantly greater localization to the plasma membrane, compared with the wild-type protein. Similarly, treatment with the calpain inhibitor, calpeptin, results in the redistribution of endogenous RCP to the periphery of the cell. We propose that once the Rab11/RCP-regulated cargo has been delivered from the endocytic recycling compartment to the plasma membrane, RCP is inactivated by calpain-mediated proteolysis.

scholarly journals Dynamin Reduces Pyk2 Y402 Phosphorylation and Src Binding in Osteoclasts

2009 ◽  
Vol 29 (13) ◽  
pp. 3644-3656 ◽  
Author(s):  
Angela Bruzzaniti ◽  
Lynn Neff ◽  
Amanda Sandoval ◽  
Liping Du ◽  
William C. Horne ◽  
...  
Keyword(s):  
Feedback Loop ◽  
Negative Feedback Loop ◽  
Dependent Manner ◽  
Colony Stimulating Factor ◽  
Tyrosine Residues ◽  
Motile Cells ◽  
Catalytically Active ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

ABSTRACT Signaling via the Pyk2-Src-Cbl complex downstream of integrins contributes to the assembly, organization, and dynamics of podosomes, which are the transient adhesion complexes of highly motile cells such as osteoclasts and dendritic cells. We previously demonstrated that the GTPase dynamin is associated with podosomes, regulates actin flux in podosomes, and promotes bone resorption by osteoclasts. We report here that dynamin associates with Pyk2, independent of dynamin's GTPase activity, and reduces Pyk2 Y402 phosphorylation in a GTPase-dependent manner, leading to decreased Src binding to Pyk2. Overexpressing dynamin decreased the macrophage colony-stimulating factor- and adhesion-induced phosphorylation of Pyk2 in osteoclastlike cells, suggesting that dynamin is likely to regulate Src-Pyk2 binding downstream of integrins and growth factor receptors with important cellular consequences. Furthermore, catalytically active Src promotes dynamin-Pyk2 association, and mutating specific Src-phosphorylated tyrosine residues in dynamin blunts the dynamin-induced decrease in Pyk2 phosphorylation. Thus, since Src binds to Pyk2 through its interaction with phospho-Y402, our results suggest that Src activates a negative-feedback loop downstream of integrin engagement and other stimuli by promoting both the binding of dynamin to Pyk2-containing complexes and the dynamin-dependent decrease in Pyk2 Y402 phosphorylation, ultimately leading to the dissociation of Src from Pyk2.

scholarly journals The Tumor-sensitive Calmodulin-like Protein Is a Specific Light Chain of Human Unconventional Myosin X

2001 ◽  
Vol 276 (15) ◽  
pp. 12182-12189 ◽  
Author(s):  
Michael S. Rogers ◽  
Emanuel E. Strehler
Keyword(s):  
Light Chain ◽  
Membrane Trafficking ◽  
Cell Periphery ◽  
Dependent Manner ◽  
Unconventional Myosin ◽  
Iq Motif ◽  
Cellular Processes ◽  
Cell Growth And Differentiation ◽  
Myosin X

Human calmodulin-like protein (CLP) is an epithelial-specific Ca2+-binding protein whose expression is strongly down-regulated in cancers. Like calmodulin, CLP is thought to regulate cellular processes via Ca2+-dependent interactions with specific target proteins. Using gel overlays, we identified a ∼210-kDa protein binding specifically and in a Ca2+-dependent manner to CLP, but not to calmodulin. Yeast two-hybrid screening yielded a CLP-interacting clone encoding the three light chain binding IQ motifs of human “unconventional” myosin X. Pull-down experiments showed CLP binding to the IQ domain to be direct and Ca2+-dependent. CLP interacted strongly with IQ motif 3 (Kd∼0.5 nm) as determined by surface plasmon resonance. Epitope-tagged myosin X was localized preferentially at the cell periphery in MCF-7 cells, and CLP colocalized with myosin X in these cells. Myosin X was able to coprecipitate CLP and, to a lesser extent, calmodulin from transfected COS-1 cells, indicating that CLP is a specific light chain of myosin Xin vivo. Because unconventional myosins participate in cellular processes ranging from membrane trafficking to signaling and cell motility, myosin X is an attractive CLP target. Altered myosin X regulation in (tumor) cells lacking CLP may have as yet unknown consequences for cell growth and differentiation.

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