GEFs (guanine nucleotide-exchange factors), which stimulate GDP dissociation from small G-proteins, are pivotal regulators of signalling pathways activated by small G-proteins. In the case of Arf proteins, which are major regulators of membrane traffic in the cell and have recently been found to be involved in an increasing number of human diseases, GDP/GTP exchange is stimulated by GEFs that c...

Abstract The Global Ensemble Forecast System (GEFS) is upgraded to version 12, in which the legacy Spectral Model (GSM) replaced by a model with new dynamical core—the Finite Volume Cubed-Sphere Dynamical Core (FV3). Extensive tests were performed determine optimal and ensemble configuration. GEFS has cubed-sphere grids horizontal resolution of about 25 km an increased size from 20 30. It exten...

cellular and molecular pathways link thrombosis and innate immune system during sepsis. extrinsic pathway activation of protease thrombin through fviia and tissue factor (tf) in sepsis help activate its endothelial cell (ec) membrane protease activated receptor 1 (par-1). thrombin adjusts the ec cycle through activation of g proteins (g12/13), and later through rho gefs (guanine nucleotide exch...

Small GTPases comprise a large and heterogeneous group of regulatory proteins that act throughout the cell as on/off switches, orchestrating processes as diverse as endocytosis at the plasma membrane to protein export from the nucleus. GTPases themselves are controlled by proteins called guanine nucleotide exchange factors (GEFs). Upon binding a GEF, the GTPase releases a molecule of GDP and pi...

Two families of GTPases, Arfs and Ypt/rabs, are key regulators of vesicular transport. While Arf proteins are implicated in vesicle budding from the donor compartment, Ypt/rab proteins are involved in the targeting of vesicles to the acceptor compartment. Recently, we have shown a role for Ypt31/32p in exit from the yeast trans-Golgi, suggesting a possible function for Ypt/rab proteins in vesic...

AIMS Rho guanine nucleotide exchange factors (Rho GEFs) are responsible for Rho protein activation by catalyzing the exchange of GDP for GTP. Although overactivation of Rho proteins is a common component of the pathogenesis of vascular disorders, the molecular mechanisms and the Rho GEFs regulating Rho protein activity and Rho-dependent functions in vascular smooth muscle cells (VSMC) are still...

UNLABELLED To establish intracellular infections, Salmonella bacteria trigger host cell membrane ruffling and invasion by subverting cellular Arf guanine nucleotide exchange factors (GEFs) that activate Arf1 and Arf6 GTPases by promoting GTP binding. A family of cellular Arf GTPase-activating proteins (GAPs) can downregulate Arf signaling by stimulating GTP hydrolysis, but whether they do this ...