Adiponutrin/PNPLA3: Proteins and Enzymes

Human ADPN (Adiponutrin; also PNPLA3 and patatin-like phospholipase domain-containing protein 3) is a 53 kDa member of the PNPLA family of phospholipase A2 enzymes. It is expressed in white adipocytes. Adiponutrin is elevated in response to insulin and appears to act not as a phospholipase, but a molecule involved in anabolic pathways. ADPN is likely to be a type II transmembrane protein that is 481 amino acids (aa) in length. It contains one patatin domain (aa 10 - 179) that is associated with in vitro enzyme activity and a transmembrane segment between aa 42 - 62. There appear to be two splice variants. One shows a four aa deletion of aa 59 - 62 and a second shows an alternate start site at Met379. Over aa 160 - 349, human ADPN shares 61% aa identity with mouse Adiponutrin.