Subcellular Localization of the Small GTPase Rab5a in Resting and Stimulated Human Neurotrophils

1997 ◽  
Vol 230 (2) ◽  
pp. 415
Author(s):  
Francesca Vita ◽  
Maria Rosa Soranzo ◽  
Violetta Borelli ◽  
Paolo Bertoncin ◽  
Giuliano Zabucchi
Keyword(s):  
Subcellular Localization ◽  
Small Gtpase

scholarly journals Influence of Subcellular Localization and Functional State on Protein Turnover

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1747
Author(s):  
Roya Yousefi ◽  
Kristina Jevdokimenko ◽  
Verena Kluever ◽  
David Pacheu-Grau ◽  
Eugenio F. Fornasiero
Keyword(s):  
Subcellular Localization ◽  
Functional State ◽  
Protein Turnover ◽  
Protein Localization ◽  
Small Gtpase ◽  
Turnover Rates ◽  
Cellular Behavior ◽  
Two Factors ◽  
Brain Creatine Kinase ◽  
Selection Of

Protein homeostasis is an equilibrium of paramount importance that maintains cellular performance by preserving an efficient proteome. This equilibrium avoids the accumulation of potentially toxic proteins, which could lead to cellular stress and death. While the regulators of proteostasis are the machineries controlling protein production, folding and degradation, several other factors can influence this process. Here, we have considered two factors influencing protein turnover: the subcellular localization of a protein and its functional state. For this purpose, we used an imaging approach based on the pulse-labeling of 17 representative SNAP-tag constructs for measuring protein lifetimes. With this approach, we obtained precise measurements of protein turnover rates in several subcellular compartments. We also tested a selection of mutants modulating the function of three extensively studied proteins, the Ca2+ sensor calmodulin, the small GTPase Rab5a and the brain creatine kinase (CKB). Finally, we followed up on the increased lifetime observed for the constitutively active Rab5a (Q79L), and we found that its stabilization correlates with enlarged endosomes and increased interaction with membranes. Overall, our data reveal that both changes in protein localization and functional state are key modulators of protein turnover, and protein lifetime fluctuations can be considered to infer changes in cellular behavior.

scholarly journals Phosphorylation by Protein Kinase Cα Regulates RalB Small GTPase Protein Activation, Subcellular Localization, and Effector Utilization

2012 ◽  
Vol 287 (18) ◽  
pp. 14827-14836 ◽  
Author(s):  
Timothy D. Martin ◽  
Natalia Mitin ◽  
Adrienne D. Cox ◽  
Jen Jen Yeh ◽  
Channing J. Der
Keyword(s):  
Protein Kinase ◽  
Subcellular Localization ◽  
Small Gtpase ◽  
Protein Activation ◽  
Protein Kinase Cα

Subcellular Localization of the Small GTPase Rab5a in Resting and Stimulated Human Neutrophils

1996 ◽  
Vol 227 (2) ◽  
pp. 367-373 ◽  
Author(s):  
Francesca Vita ◽  
Maria Rosa Soranzo ◽  
Violetta Borelli ◽  
Paolo Bertoncin ◽  
Giuliano Zabucchi
Keyword(s):  
Subcellular Localization ◽  
Small Gtpase ◽  
Human Neutrophils

Analysis of the Rac/Rop Small GTPase Family in Rice: Expression, Subcellular Localization and Role in Disease Resistance

2010 ◽  
Vol 51 (4) ◽  
pp. 585-595 ◽  
Author(s):  
L. Chen ◽  
K. Shiotani ◽  
T. Togashi ◽  
D. Miki ◽  
M. Aoyama ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Subcellular Localization ◽  
Small Gtpase

Investigating the functional link between TMEM165 and SPCA1

2019 ◽  
Vol 476 (21) ◽  
pp. 3281-3293 ◽  
Author(s):  
Elodie Lebredonchel ◽  
Marine Houdou ◽  
Hans-Heinrich Hoffmann ◽  
Kateryna Kondratska ◽  
Marie-Ange Krzewinski ◽  
...  
Keyword(s):  
Subcellular Localization ◽  
Complete Loss ◽  
Protein Family ◽  
Uncharacterized Protein ◽  
Functional Link ◽  
P Type

TMEM165 was highlighted in 2012 as the first member of the Uncharacterized Protein Family 0016 (UPF0016) related to human glycosylation diseases. Defects in TMEM165 are associated with strong Golgi glycosylation abnormalities. Our previous work has shown that TMEM165 rapidly degrades with supraphysiological manganese supplementation. In this paper, we establish a functional link between TMEM165 and SPCA1, the Golgi Ca2+/Mn2+ P-type ATPase pump. A nearly complete loss of TMEM165 was observed in SPCA1-deficient Hap1 cells. We demonstrate that TMEM165 was constitutively degraded in lysosomes in the absence of SPCA1. Complementation studies showed that TMEM165 abundance was directly dependent on SPCA1's function and more specifically its capacity to pump Mn2+ from the cytosol into the Golgi lumen. Among SPCA1 mutants that differentially impair Mn2+ and Ca2+ transport, only the Q747A mutant that favors Mn2+ pumping rescues the abundance and Golgi subcellular localization of TMEM165. Interestingly, the overexpression of SERCA2b also rescues the expression of TMEM165. Finally, this paper highlights that TMEM165 expression is linked to the function of SPCA1.

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

Subcellular localization of GLUT4 in nonstimulated and insulin-stimulated soleus muscle of rat

Diabetes ◽  
1992 ◽  
Vol 41 (2) ◽  
pp. 215-221 ◽  
Author(s):  
A. Bornemann ◽  
T. Ploug ◽  
H. Schmalbruch
Keyword(s):  
Subcellular Localization ◽  
Soleus Muscle
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