Apolipoprotein B mRNA Editing Enzyme Catalytic Polypeptide 3B (APOBEC3B)

APOBEC3B is a member of the cytidine deaminase gene family. It is one of seven related genes or pseudogenes found in a cluster, thought to result from gene duplication, on chromosome 22. Members of the cluster encode proteins that are structurally and functionally related to the C to U RNA-editing cytidine deaminase APOBEC1. It is thought that the proteins may be RNA editing enzymes and have roles in growth or cell cycle control. APOBEC3B is expressed primarily in peripheral blood leukocytes, and it was detected in most tumor cell lines examined.The deduced 235-amino acid, 28-kD protein is 89% identical to phorbolin-1, with most differences at the N terminus. Like phorbolin-1, phorbolin-1-related protein contains an RNA-editing region but fails to bind apolipoprotein B (APOB) mRNA.