Heat shock cognate
protein 70 (HSC70)

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Gene: maps to 11q23.3-q25 (Tavaria M. et al., 1995). HSC70 is the only heat shock protein 70 family member containing introns.
mRNA: size:
Protein: HSC70 is a constitutive member of the highly conserved heat shock protein 70 family, which generally comprises ~1~% of total cellular protein with possibly higher levels in transformed cells. HSC70 has several known functions: it is the uncoating ATPase for the disassembly of clathrin-coated vesicles (involved in intracellular receptor mediated transport); it is a molecular chaperone facilitating correct folding of nascent polypeptides; it enables protein translocation through the endoplasmic reticulum, nuclear membrane, and into the 26S proteasome; and it is an essential component of the centrosome, facilitating rearrangements during mitotic/meiotic spindle formation and cytoplasmic microtubule organization (Bakkenist C.J. et al., 1999).

Cell lines:

Tumors:
- HSC70 is localized to 11q23.3, a region deleted in 40% of sporadic breast and other cancers. Sequencing demonstrated mutation in the NH2-terminal ATPase domain of HSC70 in 2 of 15 sporadic breast carcinomas examined. In both cases, mutation was coincident with allelic imbalance, suggesting that HSC70 is a target of somatic mutation and deletion in a fraction of breast carcinomas. The mutations identified may affect the binding and hydrolysis of ATP and/or the binding of the two cofactors, p48 and BAG-1 (Bakkenist C.J. et al., 1999).

Bakkenist C.J. et al. (1999) Heat shock cognate 70 mutations in sporadic breast carcinoma. Cancer Res. 59, 4219-4221.
Tavaria M. et al. (1995) Localization of the gene encoding the human heat shock cognate protein, HSP73, to chromosome 11. Genomics 29, 266-268.

Under construction