Rab 19 Background Information The Ras-related superfamily of guanine nucleotide binding proteins includes the R-Ras, Rap, Ral/Rec and Rho/Rab subfamilies, all of which are thought to play an important role in either endocytosis or in biosynthetic protein transport. The process of transporting newly synthesized proteins from the endoplasmic reticulum (ER) to various stacks of the Golgi complex and to secretory vesicles involves the movement of carrier vesicles and requires Rab protein function. Rab proteins are also an integral part of endocytic pathways. Rab 19 is a 217 amino acid protein that is lipid anchored to the cytoplasmic side of the cell membrane and, as a member of the small GTPase superfamily, may play a role in endocytotic pathways. Multiple isoforms of Rab 19 exist due to alternative splicing events.
