Primary Identifier | IPR006214 | Type | Family |
Short Name | Bax_inhibitor_1-related |
description | Bax inhibitor-1 (BI-1) []is a suppressor of apoptosis that interacts with BCL2 and BCL-X. Human Bax BI-1 is an evolutionarily conserved integral membrane protein containing multiple membrane-spanning segments localised to the ER membrane. It has 6-7 membrane-spanning domains. The C termini of the mammalian BI-1 proteins are comprised of basic amino acids resembling some nuclear targeting sequences, but otherwise the predicted proteins lack motifs that suggest this function. BI-1 also regulates cell death triggered by ER stress [, , ]. BI-1 appears to exert its effect through an interaction with calmodulin []. Crystal structure of a bacterial member reveals that these proteins mediate a calcium leak across the membrane in a pH-dependent manner. Calcium homoeostasis balances passive calcium leak with active calcium uptake. The structure exists in a pore-closed and pore-open conformation, at pHs of 8 and 6 respectively [, ].This entry represents BI-1 and related sequences, including lifeguard proteins, which resemble BI-1 and also act as apoptotic regulators []. |