A membrane-associated isoform may be involved in the exocytosis of zymogens by pancreatic acini. May regulate calcium-dependent activities in the endoplasmic reticulum lumen or post-ER compartment. A membrane-associated isoform interacts with STX3 and STXBP1. Additional isoforms seem to exist. A membrane-associated isoform is expressed in acini of the pancreas (at protein level). Ubiquitous. Down-regulated by ethanol. Down-regulated during the progression of cerebellum differentiation. Binds calcium via its EF-hands. Belongs to the CREC family.