Contents

Search

heat shock protein [hsp] 70, HSP70A or HSP-A

Function: - involved in preventing misfolding of polypeptide chains - in cooperation with other chaperones, Hsp70s stabilize preexistent proteins against aggregation & mediate folding of newly translated polypeptides in the cytosol as well as within organelles - these chaperones participate in all these processes through their ability to recognize nonnative conformations of other proteins. - they bind extended peptide segments with a net hydrophobic character exposed by polypeptides during translation & membrane translocation, or following stress-induced damage - may be required to maintain protein precursors in translocation-competent form Compartment: -localizes on lysosomal membrane [4] Expression: - heat or stress induced protein Pathology: - overexpression of HSP70 protects fragile lysosomal membranes of cancer cells against lysosomal membrane permeabilization by enhancing activity of acid sphingomyelinase [4]

Interactions

molecular events

Specific

heat shock 70 kD protein 12A (HSPA12A, KIAA0417) heat shock 70 kD protein 12B (HSPA12B, C20orf60) heat shock protein [hsp] 70-3 or HSPA3 heat shock-related 70 kD protein 2; heat shock 70 kD protein 2 (HSPA2)

General

chaperonin; chaperone heat shock protein [hsp]-70 family PEST protein

Properties

SIZE: MW = 68 kD COMPARTMENT: cytoplasm cell nucleus MOTIF: ATP-binding site NAME: ATP-binding site PEST region MISC-INFO: 1/2life 1-2 HOURS pI 5.8-6.3

References

  1. Rogers S et al, Amino acids common to rapidly degraded proteins: The PEST hypothesis Science 234:364 1986 (1/2life) PMID: 2876518
  2. Craig EA, Gross CA. Is hsp70 the cellular thermometer? Trends Biochem Sci. 1991 Apr;16(4):135-40. Review. PMID: 1877088
  3. Martinus RD et al Role of chaperones in the biogenesis and maintenance of the mitochondrion. FASEB J. 1995 Mar;9(5):371-8. Review. PMID: 7896006
  4. LeGendre O, Breslin PA, Foster DA (-)-Oleocanthal rapidly and selectively induces cancer cell death via lysosomal membrane permeabilization (LMP). Molecular & Cellular Oncology. 23 Jan 2015. http://dx.doi.org/10.1080/23723556.2015.1006077

Component-of

molecular complex