scholarly journals The small GTPase Rab29 is a common regulator of immune synapse assembly and ciliogenesis

2015 ◽  
Vol 22 (10) ◽  
pp. 1687-1699 ◽  
Author(s):  
A Onnis ◽  
F Finetti ◽  
L Patrussi ◽  
M Gottardo ◽  
C Cassioli ◽  
...  
Keyword(s):  
Small Gtpase ◽  
Immune Synapse ◽  
Common Regulator

scholarly journals The small GTPase Rab8 interacts with VAMP-3 to regulate the delivery of recycling T-cell receptors to the immune synapse

2015 ◽  
Vol 128 (14) ◽  
pp. 2541-2552 ◽  
Author(s):  
Francesca Finetti ◽  
Laura Patrussi ◽  
Donatella Galgano ◽  
Chiara Cassioli ◽  
Giuseppe Perinetti ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptors ◽  
Small Gtpase ◽  
Immune Synapse ◽  
Cell Receptors

scholarly journals Rab6-dependent retrograde traffic of LAT controls immune synapse formation and T cell activation

2018 ◽  
Vol 215 (4) ◽  
pp. 1245-1265 ◽  
Author(s):  
Jean-Marie Carpier ◽  
Andres E. Zucchetti ◽  
Laurence Bataille ◽  
Stéphanie Dogniaux ◽  
Massiullah Shafaq-Zadah ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
T Lymphocyte ◽  
Cell Activation ◽  
Lymphocyte Activation ◽  
Retrograde Transport ◽  
Small Gtpase ◽  
Immune Synapse ◽  
T Lymphocyte Activation ◽  
Retrograde Traffic

The adapter molecule linker for activation of T cells (LAT) orchestrates the formation of signalosomes upon T cell receptor (TCR) stimulation. LAT is present in different intracellular pools and is dynamically recruited to the immune synapse upon stimulation. However, the intracellular traffic of LAT and its function in T lymphocyte activation are ill defined. We show herein that LAT, once internalized, transits through the Golgi–trans-Golgi network (TGN), where it is repolarized to the immune synapse. This retrograde transport of LAT depends on the small GTPase Rab6 and the target soluble N-ethylmaleimide-sensitive factor attachment protein receptor (t-SNARE) Syntaxin-16, two regulators of the endosome-to-Golgi/TGN retrograde transport. We also show in vitro in Syntaxin-16– or Rab6-silenced human cells and in vivo in CD4+ T lymphocytes of the Rab6 knockout mouse that this retrograde traffic controls TCR stimulation. These results establish that the retrograde traffic of LAT from the plasma membrane to the Golgi-TGN controls the polarized delivery of LAT at the immune synapse and T lymphocyte activation.

Small GTP-binding Protein RalA Associates with Weibel-Palade Bodies in Endothelial Cells

1999 ◽  
Vol 82 (09) ◽  
pp. 1177-1181 ◽  
Author(s):  
Hubert de Leeuw ◽  
Pauline Wijers-Koster ◽  
Jan van Mourik ◽  
Jan Voorberg
Keyword(s):  
Endothelial Cells ◽  
Binding Proteins ◽  
Binding Protein ◽  
Control Release ◽  
Small Gtpase ◽  
Gtp Binding Protein ◽  
Two Dimensional Gel Electrophoresis ◽  
Gtp Binding Proteins ◽  
Dense Granules ◽  
Gtp Binding

SummaryIn endothelial cells von Willebrand factor (vWF) and P-selectin are stored in dense granules, so-called Weibel-Palade bodies. Upon stimulation of endothelial cells with a variety of agents including thrombin, these organelles fuse with the plasma membrane and release their content. Small GTP-binding proteins have been shown to control release from intracellular storage pools in a number of cells. In this study we have investigated whether small GTP-binding proteins are associated with Weibel-Palade bodies. We isolated Weibel-Palade bodies by centrifugation on two consecutive density gradients of Percoll. The dense fraction in which these subcellular organelles were highly enriched, was analysed by SDS-PAGE followed by GTP overlay. A distinct band with an apparent molecular weight of 28,000 was observed. Two-dimensional gel electrophoresis followed by GTP overlay revealed the presence of a single small GTP-binding protein with an isoelectric point of 7.1. A monoclonal antibody directed against RalA showed reactivity with the small GTP-binding protein present in subcellular fractions that contain Weibel-Palade bodies. The small GTPase RalA was previously identified on dense granules of platelets and on synaptic vesicles in nerve terminals. Our observations suggest that RalA serves a role in regulated exocytosis of Weibel-Palade bodies in endothelial cells.

The small GTPase Rab18 modulates neuroendocrine secretion by interacting with components of the microtubule-based secretory granule transport machinery

2013 ◽  
Author(s):  
Rafael Vazquez-Martinez ◽  
Farid Almabouada ◽  
Yoana Rabanal ◽  
Alberto Diaz-Ruiz ◽  
Socorro Garcia-Navarro ◽  
...  
Keyword(s):  
Secretory Granule ◽  
Small Gtpase
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