HBXIP Antibody - #DF12276

As part of the Ragulator complex it is involved in amino acid sensing and activation of mTORC1, a signaling complex promoting cell growth in response to growth factors, energy levels, and amino acids. Activated by amino acids through a mechanism involving the lysosomal V-ATPase, the Ragulator functions as a guanine nucleotide exchange factor activating the small GTPases Rag. Activated Ragulator and Rag GTPases function as a scaffold recruiting mTORC1 to lysosomes where it is in turn activated. When complexed to BIRC5, interferes with apoptosome assembly, preventing recruitment of pro-caspase-9 to oligomerized APAF1, thereby selectively suppressing apoptosis initiated via the mitochondrial/cytochrome c pathway. Down-regulates hepatitis B virus (HBV) replication.

Cytoplasm. Lysosome.

Highly expressed in skeletal and cardiac muscle, followed by pancreas, kidney, liver, brain, placenta and lung. Elevated levels in both cancerous and non-cancerous liver tissue of patients with chronic HBV infection compared with hepatic tissue without HBV infection.

Homodimer (Probable). Part of the Ragulator complex composed of LAMTOR1, LAMTOR2, LAMTOR3, LAMTOR4 and LAMTOR5. LAMTOR4 and LAMTOR5 form a heterodimer that interacts, through LAMTOR1, with a LAMTOR2, LAMTOR3 heterodimer. The Ragulator complex interacts with both the mTORC1 complex and heterodimers constituted of the Rag GTPases RRAGA, RRAGB, RRAGC and RRAGD; regulated by amino acid availability. The Ragulator complex interacts with SLC38A9; the probable amino acid sensor. Interacts with phosphorylated BIRC5; the resulting complex binds pro-caspase-9, as well as active caspase-9, but much less efficiently. Interacts with SUPV3L1. Interacts with hepatitis B virus (HBV) oncoprotein HBX C-terminus.

Belongs to the LAMTOR5 family.