Endoplasmic reticulum (ER) chaperone that functions to stabilize non-native glycoproteins and retain them in the ER until they are properly folded or targeted for ER associated degradation (ERAD) (Probable). With co-chaperone DNJ1, coordinately maintains ER homeostasis and contributes to maintenance of cell wall architecture (PubMed:34566931). Leads to a slight growth defect at 30 degrees Celsius and marked defect at 37 degrees Celsius (PubMed:34566931). Leads to abnormal cell morphology of enlarged cells with collapsed cell walls and increased chitin within the cell walls, as well as strong growth defects at both 30 and 37 degrees Celsius when both DNJ1 and CNE1 are deleted (PubMed:34566931). Belongs to the calreticulin family.