EF-hand, calcium binding motif, found in 45 kDa calcium-binding protein (Cab45)
Cab45, also termed stromal cell-derived factor 4 (SDF-4), is a soluble, lumenal Golgi resident low-affinity Ca2+-binding protein that contains six copies of the EF-hand Ca2+-binding motif. It is required for secretory pathway calcium ATPase1 (SPCA1)-dependent Ca2+ import into the trans-Golgi network (TGN) and plays an essential role in Ca2+-dependent secretory cargo sorting at the TGN.