RAB11B
Description
The RAB11B (RAB11B, member RAS oncogene family) is a protein-coding gene located on chromosome 19.
Ras-related protein Rab-11B is a protein that in humans is encoded by the RAB11B gene. Rab11b is reported as most abundantly expressed in brain, heart and testes. Rab (Ras-related in brain) proteins form the largest section of the Ras superfamily of small GTPases. The Rab family proteins regulate intracellular membrane trafficking processes including vesicle budding, tethering, and fusion. The isoforms Rab11a, Rab11b, and Rab11c/Rab25 constitute the Rab11 subfamily based on specific sequence motifs. While RAB11A is located on chromosome 15 and RAB11C on chromosome 1, RAB11B is placed on chromosome 19. Rab11 proteins are implicated in endocytosis and exocytosis. Rab11b is reported as most abundantly expressed in brain, heart and testes. Early studies with deletions of RAB11 homologs in Saccharomyces cerevisiae proved their importance in cell survival. Despite sharing high sequence homology, Rab11a and Rab11b appear to reside within distinct vesicle compartments.
The small GTPases Rab are key regulators of intracellular membrane trafficking, from the formation of transport vesicles to their fusion with membranes. Rabs cycle between an inactive GDP-bound form and an active GTP-bound form that is able to recruit to membranes different sets of downstream effectors directly responsible for vesicle formation, movement, tethering and fusion. The small Rab GTPase RAB11B plays a role in endocytic recycling, regulating apical recycling of several transmembrane proteins including cystic fibrosis transmembrane conductance regulator/CFTR, epithelial sodium channel/ENaC, potassium voltage-gated channel, and voltage-dependent L-type calcium channel. May also regulate constitutive and regulated secretion, like insulin granule exocytosis. Required for melanosome transport and release from melanocytes. Also regulates V-ATPase intracellular transport in response to extracellular acidosis. Promotes Rabin8/RAB3IP preciliary vesicular trafficking to mother centriole by forming a ciliary targeting complex containing Rab11, ASAP1, Rabin8/RAB3IP, RAB11FIP3 and ARF4, thereby regulating ciliogenesis initiation (Probable). On the contrary, upon LPAR1 receptor signaling pathway activation, interaction with phosphorylated WDR44 prevents Rab11-RAB3IP-RAB11FIP3 complex formation and cilia growth (Probable).
RAB11B is also known as H-YPT3, NDAGSCW.
