title: Heat shock protein 70 binds to human apurinic/apyrimidinic endonuclease and stimulates endonuclease activity at abasic sites.
abstract: The interaction of human heat shock protein 70 (HSP70) with human apurinic/apyrimidinic endonuclease (HAP1) was demonstrated by coimmunoprecipitation. A combination of HSP70 and HAP1 also caused a shift in the electrophoretic mobility of a DNA fragment containing an apurinic/apyrimidinic site. The functional consequence of the HSP70/HAP1 interaction was a 10-100-fold enhancement of endonuclease activity at abasic sites. The physical and functional interaction between HSP70 and HAP1 did not require the addition of ATP. The association of HSP70 and a key base excision repair enzyme suggests a role for heat shock proteins in promoting base excision repair. These findings provide a possible mechanism by which HSP70 protects cells against oxidative stress.
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York 10467, USA.
authors.forename: M K
authors.initials: MK
authors.lastname: Kenny
authors.forename: F
authors.initials: F
authors.lastname: Mendez
authors.forename: M
authors.initials: M
authors.lastname: Sandigursky
authors.forename: R P
authors.initials: RP
authors.lastname: Kureekattil
authors.forename: J D
authors.initials: JD
authors.lastname: Goldman
authors.forename: W A
authors.initials: WA
authors.lastname: Franklin
authors.forename: R
authors.initials: R
authors.lastname: Bases
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D019757:Carbon-Oxygen Lyases / Q000378:metabolism*; D017931:DNA Primers; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D043223:Deoxyribonuclease IV (Phage T4-Induced); D004789:Enzyme Activation; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D011233:Precipitin Tests; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D017931:DNA Primers; D018840:HSP70 Heat-Shock Proteins; D011994:Recombinant Proteins; D043223:Deoxyribonuclease IV (Phage T4-Induced); D019757:Carbon-Oxygen Lyases; C085108:APEX1 protein, human; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase