VPS39 Antibody - #DF12794

Regulator of TGF-beta/activin signaling, inhibiting SMAD3- and activating SMAD2-dependent transcription. Acts by interfering with SMAD3/SMAD4 complex formation, this would lead to inhibition of SMAD3-dependent transcription and relieve SMAD3 inhibition of SMAD2-dependent promoters, thus increasing SMAD2-dependent transcription. Does not affect TGF-beta-induced SMAD2 or SMAD3 phosphorylation, nor SMAD2/SMAD4 complex formation.

Plays a role in vesicle-mediated protein trafficking to lysosomal compartments including the endocytic membrane transport and autophagic pathways. Believed to act in part as a component of the putative HOPS endosomal tethering complex which is proposed to be involved in the Rab5-to-Rab7 endosome conversion probably implicating MON1A/B, and via binding SNAREs and SNARE complexes to mediate tethering and docking events during SNARE-mediated membrane fusion. The HOPS complex is proposed to be recruited to Rab7 on the late endosomal membrane and to regulate late endocytic, phagocytic and autophagic traffic towards lysosomes. Involved in homotypic vesicle fusions between late endosomes and in heterotypic fusions between late endosomes and lysosomes. Required for fusion of endosomes and autophagosomes with lysosomes.

Cytoplasm. Lysosome membrane>Peripheral membrane protein. Late endosome membrane>Peripheral membrane protein. Late endosome. Lysosome.
Note: Colocalizes with TGFBR1 and TGFBR2 in cytoplasmic vesicular structures and most prominently in cortical vesicles.

Widely expressed, with highest levels in heart, skeletal muscle, kidney, pancreas, brain, placenta and spleen.

Homooligomer. Interacts with TGFBR2 and, less efficiently, with TGFBR1; interaction with TGFBR2 is independent of the receptor kinase activity and of the presence of TGF-beta. Also interacts with ACVR2B, but not with BMPR2. Interacts with SMAD4, preferentially following TGF-beta treatment. Does not interact with SAMD2 or SMAD3. Component of the putative homotypic fusion and vacuole protein sorting (HOPS) complex; the core of which composed of the class C Vps proteins VPS11, VPS16, VPS18 and VPS33A, is associated with VPS39 and VPS41. Interacts with PLEKHM2; involved in VPS39 recruitment to ARL8B-containing lysosomes. Associates with adaptor protein complex 3 (AP-3) and clathrin:AP-3 complexes (By similarity).

Belongs to the VAM6/VPS39 family.