GRASP55 (Golgi re-assembly stacking protein of 55 kDa) and GRASP65 (a 65 kDa) protein are highly homologous. GRASP55 is a component of the Golgi stacking machinery. GRASP65, an N-ethylmaleimide- sensitive membrane protein required for the stacking of Golgi cisternae in a cell-free system [1]. This region appears to be related to the PDZ domain.

1: GRASP55, a second mammalian GRASP protein involved in the stacking of Golgi cisternae in a cell-free system. Shorter J, Watson R, Giannakou ME, Clarke M, Warren G, Barr FA; EMBO J 1999;18:4949-4960. PMID:10487747