BAG6(redirected from HLA-B-associated transcript 3)
BAG6A gene on chromosome 6p21.3 that encodes a chaperone which plays a key role in various processes, such as DNA damage-induced apoptosis, insertion of tail-anchored (TA) membrane proteins in the endoplasmic reticulum membrane and regulation of chromatin. BAG6/BAT3 acts by facilitating tail-anchored (TA) membrane proteins captured by ASNA1/TRC40: it is recruited to ribosomes synthesising membrane proteins, interacts with the transmembrane region of newly released TA proteins and transfers them to ASNA1/TRC40 for targeting to the endoplasmic reticulum membrane. BAG6 is required:
• During spermatogenesis for synaptonemal complex assembly via its interaction with HSPA2, by inhibiting polyubiquitination and subsequent proteasomal degradation of HSPA2; and
• For selective ubiquitin-mediated degradation of defective nascent chain polypeptides by the proteasome; it may play a role in immuno-proteasomes, generating antigenic peptides via targeted degradation, thereby playing a role in antigen presentation in immune response.