Anti-phospho Rab1 (Thr75) from rabbit

Ras-related protein Rab-1A (UniProt: P62820; also known as YPT1-related protein) is encoded by the RAB1A (also known as RAB1) gene (Gene ID: 5861) in human. Rab1 is a member of the small GTPase superfamily. Rab proteins are the largest family of small Ras-like GTPases. Three isoforms of Rab1 have been reported that are produced by alternative splicing. Rab GTPases are key regulators of intracellular membrane trafficking, from the formation of transport vesicles to their fusion with membranes. They cycle between an inactive GDP-bound form and an active GTP-bound form, which is able to recruit to membranes different sets of downstream effectors directly responsible for vesicle formation, movement, tethering, and fusion. Rab1 is reported to regulate vesicular protein transport from the endoplasmic reticulum (ER) to the Golgi compartment and on to the cell surface. Rab1 is also shown to be involved in autophagosome assembly and cellular defense reactions against pathogenic bacteria. Rab1 is shown to be phosphorylated at Thr75 by TGF-beta activated kinase 1 (TAK1), which preferentially phosphorylates the inactive (GDP-bound) state of Rab1. Phosphorylation disrupts interaction with GDP dissociation inhibitor 1 (GDI1), but not GEF or GAP. Phosphorylation at Thr75 is shown to be essential for Rab1 function.