DnaJ homolog subfamily B member 12 (DNAJB12)

Acts as a co-chaperone with HSPA8/Hsc70; required to promote protein folding and trafficking, prevent aggregation of client proteins, and encourage unfolded proteins into endoplasmic reticulum-associated degradation (ERAD) pathway (PubMed:21150129, PubMed:21148293). Acts by discovering HSPA8/Hsc70's ATPase and polypeptide-binding actions.

Can also act independently of HSPA8/Hsc70: together with DNAJB14, acts as a chaperone that promotes maturation of potassium channels KCND2 and KCNH2 by stabilizing nascent channel subunits and building them into tetramers (PubMed:27916661). While stabilization of nascent channel proteins depends on HSPA8/Hsc70, the process of oligomerization of channel subunits is independent of HSPA8/Hsc70 (PubMed:27916661).