it was originally suggested that the ins ( 1,4,5 ) p3-sensitive store is the endoplasmic reticulum , but a new organelle , the calciosome , identified by its possession of the calcium-binding protein , calsequestrin , and a ca2+-atpase-like protein of relative molecular mass 100,000 ( 100k ) , has been described as a potential ins ( 1,4,5 ) p3-sensitive calcium store .
C0006732
calcium-binding protein
C0006787
calsequestrin