Interaction of Hsp70 with p49/STRAP, a serum response factor binding protein.
Members of the Hsp70 protein family must work with other co-chaperones to exert their function. Herein, we identified a new Hsp70 co-chaperone, p49/STRAP, previously shown to interact with serum response factor. We demonstrated that a fraction of p49/STRAP was cytosolic, and that it interacted with the beta-sandwich domain of Hsp70. Although p49/STRAP had little effect on the intrinsic ATPase activity of Hsp70, it reduced the ATP-hydrolytic activity of Hsp70 stimulated by Hsp40, and inhibited the refolding activity of the Hsp70/Hsp40 system. Thus, p49/STRAP can be considered a bona fide co-chaperone of Hsp70.
Lin
Jyun-Liang
JL
Institute of Molecular Biology, Academia Sinica, 128 Academia Rd., Taipei, Taiwan.
Liu
Fu-Hwa
FH
Wang
Chung
C
D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
D018840:HSP70 Heat-Shock Proteins; D018832:Molecular Chaperones; C496545:SRFBP1 protein, human; D014157:Transcription Factors