This family of transmembrane proteins is found in eukaryotes. Proteins in this family are typically between 213 and 245 amino acids in length. It is found in various tissues, including the brain, liver and kidneys. It was first discovered as a functional unknown gene, murine brain I3 (BRI3). This protein is also known as HCCRBP-1 and it plays a role in tumourigenesis, as it binds to an oncogene, HCCR-1, and acts as a negative regulator of p53/TP53 tumour suppressor. BRI3BP induces tumourigenesis by activating protein kinase C (PKC) activity but decreasing the pro-apoptotic PKC-alpha and PKC-delta isoform levels. BRI3BP is over-expressed in many tumours [1].

1: HCCRBP-1 directly interacting with HCCR-1 induces tumorigenesis through P53 stabilization. Ha SA, Shin SM, Lee YJ, Kim S, Kim HK, Namkoong H, Lee H, Lee YS, Cho YS, Park YG, Jeon HM, Oh C, Kim JW; Int J Cancer. 2008;122:501-508. PMID:17943721