VPS33B Antibody – Mouse Polyclonal

Vesicle mediated protein sorting plays an important role in segregation of intracellular molecules into distinct organelles. Genetic studies in yeast have identified more than 40 vacuolar protein sorting (VPS) genes involved in vesicle transport to vacuoles. This gene is a member of the Sec-1 domain family, and encodes the human ortholog of rat Vps33b which is homologous to the yeast class C Vps33 protein. The mammalian class C Vps proteins are predominantly associated with late endosomes/lysosomes, and like their yeast counterparts, may mediate vesicle trafficking steps in the endosome/lysosome pathway. [provided by RefSeq, Jul 2008]

Function: May play a role in vesicle-mediated protein trafficking to lysosomal compartments and in membrane docking/fusion reactions of late endosomes/lysosomes. Mediates phagolysosomal fusion in macrophages. Ref.6

Subunit structure: Interacts with RAB11A and VIPAS39. Interacts with M.tuberculosis PtpA. Ref.6 Ref.8

Subcellular location: Late endosome membrane; Peripheral membrane protein; Cytoplasmic side. Lysosome membrane; Peripheral membrane protein; Cytoplasmic side. Note: Cytoplasmic, peripheral membrane protein associated with late endosomes/lysosomes. Colocalizes with M.tuberculosis PtpA in the cytosol of tuberculosis-infected macrophages and associates with phagosomes. Colocalizes in clusters with VIPAS39 at cytoplasmic organelles. Ref.6 Ref.8 Ref.10

Tissue specificity: Ubiquitous; highly expressed in testis and low expression in the lung.

Post-translational modification: Phosphorylated on tyrosine residues. Dephosphorylation by M.tuberculosis PtpA is necessary to induce the reduction of host phagolysosome fusion in M.tuberculosis-infected macrophages. Ref.6

Involvement in disease: Arthrogryposis, renal dysfunction and cholestasis syndrome 1 (ARCS1) [MIM:208085]: A multisystem disorder, characterized by neurogenic arthrogryposis multiplex congenita, renal tubular dysfunction and neonatal cholestasis with bile duct hypoplasia and low gamma glutamyl transpeptidase activity. Platelet dysfunction is common.Note: The disease is caused by mutations affecting the gene represented in this entry. Ref.8 Ref.10 Ref.11

Sequence similarities: Belongs to the STXBP/unc-18/SEC1 family.

Caution: According to Ref.6, it is autophosphorylated. However, it is not related with protein kinases, suggesting it is phosphorylated by another protein.