title: Rho GTPases in platelet function.
abstract: The Rho family of GTP binding proteins, also commonly referred to as the Rho GTPases, are master regulators of the platelet cytoskeleton and platelet function. These low-molecular-weight or 'small' GTPases act as signaling switches in the spatial and temporal transduction, and amplification of signals from platelet cell surface receptors to the intracellular signaling pathways that drive platelet function. The Rho GTPase family members RhoA, Cdc42 and Rac1 have emerged as key regulators in the dynamics of the actin cytoskeleton in platelets and play key roles in platelet aggregation, secretion, spreading and thrombus formation. Rho GTPase regulators, including GEFs and GAPs and downstream effectors, such as the WASPs, formins and PAKs, may also regulate platelet activation and function. In this review, we provide an overview of Rho GTPase signaling in platelet physiology. Previous studies of Rho GTPases and platelets have had a shared history, as platelets have served as an ideal, non-transformed cellular model to characterize Rho function. Likewise, recent studies of the cell biology of Rho GTPase family members have helped to build an understanding of the molecular regulation of platelet function and will continue to do so through the further characterization of Rho GTPases as well as Rho GAPs, GEFs, RhoGDIs and Rho effectors in actin reorganization and other Rho-driven cellular processes.
authors.affiliation: Department of Biomedical Engineering and Cell & Developmental Biology, School of Medicine, Oregon Health & Science University, Portland, OR 97239, USA. aslanj@ohsu.edu
authors.forename: J E
authors.initials: JE
authors.lastname: Aslan
authors.forename: O J T
authors.initials: OJ
authors.lastname: McCarty
mesh_terms: D008841:Actin Cytoskeleton / Q000201:enzymology; D000818:Animals; D001792:Blood Platelets / Q000201:enzymology*; D048430:Cell Shape; D020690:GTPase-Activating Proteins / Q000097:blood; D020662:Guanine Nucleotide Exchange Factors / Q000097:blood; D006801:Humans; D015539:Platelet Activation; D011554:Pseudopodia / Q000201:enzymology; D015398:Signal Transduction; D013927:Thrombosis / Q000097:blood / Q000201:enzymology*; D020764:cdc42 GTP-Binding Protein / Q000097:blood; D054462:p21-Activated Kinases / Q000097:blood; D020744:rac GTP-Binding Proteins / Q000097:blood; D020741:rho GTP-Binding Proteins / Q000097:blood*; D062947:rho-Specific Guanine Nucleotide Dissociation Inhibitors / Q000097:blood; D020742:rhoA GTP-Binding Protein / Q000097:blood
chemical_list: D020690:GTPase-Activating Proteins; D020662:Guanine Nucleotide Exchange Factors; D062947:rho-Specific Guanine Nucleotide Dissociation Inhibitors; D054462:p21-Activated Kinases; D020764:cdc42 GTP-Binding Protein; D020744:rac GTP-Binding Proteins; D020741:rho GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein