GRAF1-dependent endocytosis

2009 ◽  
Vol 37 (5) ◽  
pp. 1061-1065 ◽  
Author(s):  
Gary J. Doherty ◽  
Richard Lundmark
Keyword(s):  
G Protein ◽  
Extracellular Fluid ◽  
Endocytic Pathway ◽  
Protein Domain ◽  
Small G Protein ◽  
G Protein Signalling ◽  
Protein Functions ◽  
Membrane Carriers

The role of endocytosis in controlling a multitude of cell biological events is well established. Molecular and mechanistic characterization of endocytosis has predominantly focused on CME (clathrin-mediated endocytosis), although many other endocytic pathways have been described. It was recently shown that the BAR (Bin/amphiphysin/Rvs) and Rho GAP (GTPase-activating protein) domain-containing protein GRAF1 (GTPase regulator associated with focal adhesion kinase-1) is found on prevalent, pleiomorphic endocytic membranes, and is essential for the major, clathrin-independent endocytic pathway that these membranes mediate. This pathway is characterized by its ability to internalize GPI (glycosylphosphatidylinositol)-anchored proteins, bacterial toxins and large amounts of extracellular fluid. These membrane carriers are highly dynamic and associated with the activity of the small G-protein Cdc42 (cell division cycle 42). In the present paper, we review the role of GRAF1 in this CLIC (clathrin-independent carrier)/GEEC (GPI-anchored protein-enriched early endocytic compartment) endocytic pathway and discuss the current understanding regarding how this multidomain protein functions at the interface between membrane sculpting, small G-protein signalling and endocytosis.

scholarly journals The dynamic role of regulator of G-protein signalling (RGS) proteins in partial agonism

2014 ◽  
Vol 592 (17) ◽  
pp. 3701-3702
Author(s):  
Joobin Sattar ◽  
Kevin P. Grace ◽  
Guillaume Bastin
Keyword(s):  
G Protein ◽  
Rgs Proteins ◽  
Partial Agonism ◽  
G Protein Signalling

scholarly journals Allosteric switch regulates protein–protein binding through collective motion

2016 ◽  
Vol 113 (12) ◽  
pp. 3269-3274 ◽  
Author(s):  
Colin A. Smith ◽  
David Ban ◽  
Supriya Pratihar ◽  
Karin Giller ◽  
Maria Paulat ◽  
...  
Keyword(s):  
Collective Motion ◽  
Protein Domain ◽  
Allosteric Coupling ◽  
Allosteric Communication ◽  
Binding Interface ◽  
Specific Protease ◽  
Ubiquitin Specific Protease ◽  
Promising Avenue

Many biological processes depend on allosteric communication between different parts of a protein, but the role of internal protein motion in propagating signals through the structure remains largely unknown. Through an experimental and computational analysis of the ground state dynamics in ubiquitin, we identify a collective global motion that is specifically linked to a conformational switch distant from the binding interface. This allosteric coupling is also present in crystal structures and is found to facilitate multispecificity, particularly binding to the ubiquitin-specific protease (USP) family of deubiquitinases. The collective motion that enables this allosteric communication does not affect binding through localized changes but, instead, depends on expansion and contraction of the entire protein domain. The characterization of these collective motions represents a promising avenue for finding and manipulating allosteric networks.

Cloning and characterization of a novel regulator of G protein signalling in human platelets

2002 ◽  
Vol 14 (7) ◽  
pp. 595-606 ◽  
Author(s):  
Alison W. Gagnon ◽  
David L. Murray ◽  
Robert J. Leadley
Keyword(s):  
G Protein ◽  
Human Platelets ◽  
G Protein Signalling

scholarly journals Molecular Characterization of NDL1-AGB1 Mediated Salt Stress Signaling: Further Exploration of the Role of NDL1 Interacting Partners

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2261
Author(s):  
Nidhi Gupta ◽  
Abhishek Kanojia ◽  
Arpana Katiyar ◽  
Yashwanti Mudgil
Keyword(s):  
Salt Stress ◽  
Stress Response ◽  
G Protein ◽  
Salinity Stress ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Negative Regulator ◽  
Salt Stress Response

Salt stress is considered to be the most severe abiotic stress. High soil salinity leads to osmotic and ionic toxicity, resulting in reduced plant growth and crop production. The role of G-proteins during salt stresses is well established. AGB1, a G-protein subunit, not only plays an important role during regulation of Na+ fluxes in roots, but is also involved in the translocation of Na+ from roots to shoots. N-Myc Downregulated like 1 (NDL1) is an interacting partner of G protein βγ subunits and C-4 domain of RGS1 in Arabidopsis. Our recent in-planta expression analysis of NDL1 reported changes in patterns during salt stress. Based on these expression profiles, we have carried out functional characterization of the AGB1-NDL1 module during salinity stress. Using various available mutant and overexpression lines of NDL1 and AGB1, we found that NDL1 acts as a negative regulator during salt stress response at the seedling stage, an opposite response to that of AGB1. On the other hand, during the germination phase of the plant, this role is reversed, indicating developmental and tissue specific regulation. To elucidate the mechanism of the AGB1-NDL1 module, we investigated the possible role of the three NDL1 stress specific interactors, namely ANNAT1, SLT1, and IDH-V, using yeast as a model. The present study revealed that NDL1 acts as a modulator of salt stress response, wherein it can have both positive as well as negative functions during salinity stress. Our findings suggest that the NDL1 mediated stress response depends on its developmental stage-specific expression patterns as well as the differential presence and interaction of the stress-specific interactors.

scholarly journals G protein-regulated endocytic trafficking of adenylyl cyclase type 9

2020 ◽  
Author(s):  
André M. Lazar ◽  
Roshanak Irannejad ◽  
Tanya A. Baldwin ◽  
Aparna A. Sundaram ◽  
J. Silvio Gutkind ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Adenylyl Cyclase ◽  
G Protein ◽  
Subcellular Location ◽  
Endocytic Pathway ◽  
Heterotrimeric G Proteins ◽  
Camp Production ◽  
Stimulation Of

SummaryGPCRs are increasingly recognized to initiate signaling via heterotrimeric G proteins as they move through the endocytic network, but little is known about how relevant G protein effectors are localized. Here we report dynamic trafficking of adenylyl cyclase type 9 (AC9) from the plasma membrane to endosomes, while adenylyl cyclase type 1 (AC1) remains in the plasma membrane, and stimulation of AC9 trafficking by ligand-induced activation of Gs-coupled GPCRs or Gs. AC9 transits a similar dynamin-dependent early endocytic pathway as activated GPCRs but, in contrast to GPCR trafficking which is regulated by β-arrestin but not Gs, AC9 trafficking is regulated by Gs but not β-arrestin. We also show that AC9, but not AC1, contributes to cAMP production from endosomes. These results reveal dynamic and isoform-specific trafficking of adenylyl cyclase in the endocytic network, and a discrete role of a heterotrimeric G protein in controlling subcellular location of a relevant effector.

Expression and characterization of Rab38, a new member of the Rab small G protein family

2005 ◽  
Vol 386 (2) ◽  
Author(s):  
Kazuhiro Osanai ◽  
Keiji Takahashi ◽  
Katsumi Nakamura ◽  
Masakatsu Takahashi ◽  
Masanobu Ishigaki ◽  
...  
Keyword(s):  
G Protein ◽  
Protein Family ◽  
Small G Protein

scholarly journals Potential Contributory Role of H-Ras, a Small G-Protein, in the Development of Retinopathy in Diabetic Rats

Diabetes ◽  
2004 ◽  
Vol 53 (3) ◽  
pp. 775-783 ◽  
Author(s):  
R. A. Kowluru ◽  
A. Kowluru ◽  
S. Chakrabarti ◽  
Z. Khan
Keyword(s):  
G Protein ◽  
Diabetic Rats ◽  
Small G Protein

scholarly journals A Novel Role of Nectins in Inhibition of the E-Cadherin–induced Activation of Rac and Formation of Cell-Cell Adherens Junctions

2004 ◽  
Vol 15 (3) ◽  
pp. 1077-1088 ◽  
Author(s):  
Takashi Hoshino ◽  
Kazuya Shimizu ◽  
Tomoyuki Honda ◽  
Tomomi Kawakatsu ◽  
Taihei Fukuyama ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
G Protein ◽  
Adherens Junctions ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Inhibitory Effect ◽  
Small G Protein ◽  
E Cadherin ◽  
Cell Cell

Nectins are Ca2+-independent immunoglobulin (Ig)-like cell-cell adhesion molecules. The trans-interactions of nectins recruit cadherins to the nectin-based cell-cell adhesion, resulting in formation of cell-cell adherens junctions (AJs) in epithelial cells and fibroblasts. The trans-interaction of E-cadherin induces activation of Rac small G protein, whereas the trans-interactions of nectins induce activation of not only Rac but also Cdc42 small G protein. We showed by the fluorescent resonance energy transfer (FRET) imaging that the trans-interaction of E-cadherin induced dynamic activation and inactivation of Rac, which led to dynamic formation and retraction of lamellipodia. Moreover, we found here that the nectins, which did not trans-interact with other nectins (non–trans-interacting nectins), inhibited the E-cadherin–induced activation of Rac and reduced the velocity of the formation of the E-cadherin-based cell-cell AJs. The inhibitory effect of non–trans-interacting nectins was suppressed by the activation of Cdc42 induced by the trans-interactions of nectins. These results indicate a novel role of nectins in regulation of the E-cadherin–induced activation of Rac and formation of cell-cell AJs.

scholarly journals G-protein signalling pathways and oestrogen: a role of balanced maintenance in osteoblasts

1999 ◽  
Vol 1449 (3) ◽  
pp. 284-292 ◽  
Author(s):  
Stelios Papaioannou ◽  
Anthony M. Tumber ◽  
Murray C. Meikle ◽  
Fraser McDonald
Keyword(s):  
G Protein ◽  
Signalling Pathways ◽  
G Protein Signalling
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