The Ras-superfamily of small G proteins is a family of GTP hydrolases that is regulated by GTP/GDP binding states. One member of the Ras-superfamily, Rab, is involved in the regulation of vesicle trafficking, which is critical to endocytosis, biosynthesis, secretion, cell differentiation and cell growth. The active form of the Rab proteins, which contains GTP, can recruit specific binding partn...

cAMP (3',5' cyclic adenosine monophosphate) is a second messenger that in eukaryotic cells induces physiological responses ranging from growth, differentiation, and gene expression to secretion and neurotransmission. Most of these effects have been attributed to the binding of cAMP to cAMP-dependent protein kinase A (PKA). Here, a family of cAMP-binding proteins that are differentially distribu...

Membrane/ protein trafficking in the secretory/ biosynthetic and endocytic pathways is mediated by vesicles. Vesicle trafficking in eukaryotes is regulated by a class of small monomeric GTPases the Rab protein family. Rab proteins represent the largest branch of the Ras superfamily GTPases, and have been concerned in a variety of intracellular vesicle trafficking and different intracellular sig...

Introduction The Rho family is part of the Ras superfamily of small GTP-binding proteins, and consists of Rho (A, B and C), Rac (1 and 2), two Cdc42 isoforms, RhoD, RhoE, RhoG, TClO and TTF [l]. Different members of the large Ras superfamily regulate a diverse array of cellular processes, from vesicle trafficking to signal transduction. They all have in common the ability to bind and hydrolyse ...

Cdc42p, a Rho family GTPase of the Ras superfamily, is a key regulator of cell polarity and morphogenesis in eukaryotes. Using 37 site-directed cdc42 mutants, we explored the functions and interactions of Cdc42p in the budding yeast Saccharomyces cerevisiae. Cytological and genetic analyses of these cdc42 mutants revealed novel and diverse phenotypes, showing that Cdc42p possesses at least two ...

Although the human Ras proteins are members of a large superfamily of Ras-related proteins, to date, only the proteins encoded by the three mammalian ras genes have been found to possess oncogenic potential. Among the known Ras-related proteins, TC21/R-Ras2 exhibits the most significant amino acid identity (55%) to Ras proteins. We have generated mutant forms of TC21 that possess amino acid sub...