Heat shock protein family A member 13 (HSPA13)

Heat shock protein family A member 13 (HSPA13) is a human protein encoded by the *HSPA13* gene and is a member of the HSP70 family, though it differs from canonical HSP70s by lacking a substrate-binding domain[2][4]. HSPA13 localizes to the endoplasmic reticulum (ER) and the ER membrane and plays a central role in the regulation of protein import through the ER translocon complex (including Sec61 and associated factors), assisting the proper folding, processing, and quality control of cytosolic and secretory proteins[4]. It possesses peptide-independent ATPase activity and is a stress-inducible gene regulated by the unfolded protein response[2][4]. HSPA13 promotes ER and cytoplasmic proteostasis, and its aberrant expression is implicated in several cancers—where it promotes proliferation, migration, and invasion (notably in hepatocellular carcinoma)—by stabilizing regulatory proteins such as TANK and modulating their degradation via the ubiquitin–proteasome pathway[1]. HSPA13 has also been implicated in plasma cell differentiation, ER stress response, and protein folding diseases such as prion disorders[1][4]. No specific drugs currently target HSPA13 directly, and mechanisms of drug action or therapeutic safety profiles have not been well-established. Its emerging roles in both oncogenesis and proteostasis present potential therapeutic opportunities and challenges.

Other names

Heat shock 70 kDa protein 13STCHMicrosomal stress-70 protein ATPase coreStress-70 protein chaperone microsome-associated 60 kDa proteinTestis secretory sperm-binding protein Li 199a