The YPT-Branch of the ras Superfamily of GTP-Binding Proteins in Yeast: Functional Importance of the Putative Effector Region
Résumé
Both in unicellular and multicellular organisms, a large number of structurally related small GTP-binding proteins, collectively known as ras superfamily of proteins, has been identified within the past few years. These proteins are similar in size and they share highly conserved sequence motifs which, in the case of H-ras p21, have been demonstrated to be contact regions for the bound nucleotide (see 1,2 for review). It is thought, and in very few cases it is known, that the diverse members of this superfamily of proteins are regulators of basic cellular processes, including the transmission of proliferation signals, the vectorial transport and the fusion of vesicles, the proper functioning of the cytoskeleton and cell differentiation (see 1–3 for review).