Sorting Nexin 21 (SNX21)

Sorting nexin-21 is a member of the sorting nexin family. Members of this family contain a phox (PX) domain, which is a phosphoinositide binding domain, and are involved in intracellular trafficking. This protein does not contain a coiled coil region, like some family members. The specific function of this protein has not been determined. Multiple transcript variants encoding distinct isoforms have been identified for this gene.Highly expressed in fetus liver, but only weakly expressed in brain, skeleton muscle, smooth muscle, and cardiac muscle, kidney, and adrenal gland.Sorting nexins are a large group of proteins with the common characteristic of having a PX domain (a phospholipid-binding motif).Some members of this family have been shown to facilitate protein sorting.