N-terminal phospholipase D-like domain of proteins from the Family with sequence similarity 83
N-terminal phospholipase D (PLD)-like domain of vetebrate proteins from the Family with sequence similarity 83 (FAM83), which is comprised of 8 members, designated FAM83A through FAM83H. Since the N-terminal PLD-like domain of FAM83 proteins shows only trace similarity to the PLD catalytic domain and lacks the functionally important histidine residue, the FAM83 proteins may share a similar three-dimensional fold with PLD enzymes, but are unlikely to carry PLD activity. Members of the FAM83 are mostly uncharacterized proteins. FAM83A, also known as tumor antigen BJ-TSA-9, is a novel tumor-specific gene highly expressed in human lung adenocarcinoma. FAM83D, also known as spindle protein CHICA, is a cell-cycle-regulated spindle component which localizes to the mitotic spindle and is both upregulated and phosphorylated during mitosis. The gene encoding protein FAM83H is the first gene involved in the etiology of amelogenesis imperfecta (AI), that encodes a non-secreted protein due to the absence of a signal peptide. Defects in gene FAM83H cause autosomal dominant hypocalcified amelogenesis imperfecta (ADHCAI). FAM83B, FAM83C, FAM83F, and FAM83G are uncharacterized proteins present across vertebrates while FAM83E is an uncharacterized protein found only in mammals.