Small GTP-binding protein RhoB is expressed in glial müller cells in the vertebrate retina

2005 ◽  
Vol 494 (6) ◽  
pp. 976-985 ◽  
Author(s):  
Andréa Silveira Santos-Bredariol ◽  
Mônica Aparecida Belmonte ◽  
Alexandre Hiroaki Kihara ◽  
Marinilce Fagundes Santos ◽  
Dânia Emi Hamassaki
Keyword(s):  
Binding Protein ◽  
Müller Cells ◽  
Muller Cells ◽  
Gtp Binding Protein ◽  
Vertebrate Retina ◽  
Gtp Binding

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.

Rap1b Association with the Platelet Cytoskeleton Occurs in the Absence of Glycoproteins IIb/IIIa

1998 ◽  
Vol 79 (04) ◽  
pp. 832-836 ◽  
Author(s):  
Thomas Fischer ◽  
Christina Duffy ◽  
Gilbert White
Keyword(s):  
Molecular Weight ◽  
Divalent Cation ◽  
Binding Proteins ◽  
Binding Protein ◽  
Platelet Membrane ◽  
Low Molecular Weight ◽  
Membrane Glycoproteins ◽  
Gtp Binding Protein ◽  
Gtp Binding Proteins ◽  
Gtp Binding

SummaryPlatelet membrane glycoproteins (GP) IIb/IIIa and rap1b, a 21 kDa GTP binding protein, associate with the triton-insoluble, activation-dependent platelet cytoskeleton with similar rates and divalent cation requirement. To examine the possibility that GPIIb/IIIa was required for rap1b association with the cytoskeleton, experiments were performed to determine if the two proteins were linked under various conditions. Chromatography of lysates from resting platelets on Sephacryl S-300 showed that GPIIb/IIIa and rap1b were well separated and distinct proteins. Immunoprecipitation of GPIIb/IIIa from lysates of resting platelets did not produce rap1b or other low molecular weight GTP binding proteins and immunoprecipitation of rap1b from lysates of resting platelets did not produce GPIIb/IIIa. Finally, rap1b was associated with the activation-dependent cytoskeleton of platelets from a patient with Glanzmann’s thrombasthenia who lacks surface expressed glycoproteins IIb and IIIa. Based on these findings, we conclude that no association between GPIIb/IIIa and rap1b is found in resting platelets and that rap1b association with the activation-dependent cytoskeleton is at least partly independent of GPIIb/IIIa.

Characterization and Functional Analysis of a Small GTP-binding Protein AtRAB Interacting with H+-pyrophosphatase AVP1 inArabidopsis thaliana

2014 ◽  
Vol 40 (10) ◽  
pp. 1756
Author(s):  
Rong-Bang LIU ◽  
Ming CHEN ◽  
Meng-Meng GUO ◽  
Qing-Lin SI ◽  
Shi-Qing GAO ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Binding Protein ◽  
Gtp Binding Protein ◽  
Gtp Binding

Crystal Structure of the GTP-binding Protein Obg from Thermus thermophilus HB8

2004 ◽  
Vol 337 (3) ◽  
pp. 761-770 ◽  
Author(s):  
Mutsuko Kukimoto-Niino ◽  
Kazutaka Murayama ◽  
Mio Inoue ◽  
Takaho Terada ◽  
Jeremy R.H. Tame ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Binding Protein ◽  
Thermus Thermophilus ◽  
Gtp Binding Protein ◽  
Thermus Thermophilus Hb8 ◽  
Gtp Binding
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