Endoplasmic reticulum disulfide reductase that collaborates directly with the chaperone BIP/HSPA5 (GRP78) to maintain protein quality control by facilitating either the correct folding or the targeted degradation of misfolded proteins (PubMed:12411443, PubMed:23769672, PubMed:37739037). Essential for efficient maturation of newly synthesized polypeptides in the endoplasmic reticulum, binds to substrate proteins and specifically catalyzes the reduction and removal of improper (non-native) disulfide bonds during the folding process (PubMed:23769672, PubMed:37739037). In endoplasmic reticulum- associated degradation (ERAD), DNAJC10 reduces incorrect disulfide bonds specifically in misfolded glycoproteins that have been recognized by EDEM1, a key component of the ERAD pathway, thereby enabling their retrotranslocation and degradation (PubMed:18400946). Promotes apoptotic signaling pathway in response to endoplasmic reticulum stress (PubMed:19122239). {ECO:0000269|PubMed:12411443, ECO:0000269|PubMed:18400946, ECO:0000269|PubMed:19122239, ECO:0000269|PubMed:23769672, ECO:0000269|PubMed:37739037}. This is the function of ENSG00000077232 (DNAJC10, DnaJ heat shock protein family (Hsp40) member C10).