N-terminal phospholipase D-like domain of the uncharacterized protein, Family with sequence similarity 83H
N-terminal phospholipase D (PLD)-like domain of the protein, Family with sequence similarity 83H (FAM83H) on chromosome 8q24.3, which localizes in the intracellular environment and is associated with vesicles, can be regulated by kinases, and plays important roles during ameloblast differentiation and enamel matrix calcification. 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). Since the N-terminal PLD-like domain of FAM83H shows only trace similarity to the PLD catalytic domain and lacks the functionally important histidine residue, FAM83H may share a similar three-dimensional fold with PLD enzymes, but is most unlikely to carry PLD activity.