Role of the C-terminal region of mouse inducible Hsp72 in the recognition of peptide substrate for chaperone activity.
Here, we produced the C-terminal truncation variants of mouse inducible heat shock protein 72 (Hsp72) to elucidate the regulatory role of the C-terminal helical lid of Hsp70 for substrate recognition. All of the truncation variants containing the substrate binding domain bound a short-length peptide substrate CLLLSAPRR. When a large mass reduced carboxymethyl alpha-lactalbumin (RCMLA) as a substrate was used in gel filtration experiment, we observed the complex formation only for the truncation variants containing the long alpha-helix C in the helical lid. However, RCMLA binding occurred even for the variants lacking alpha-helix C when their C-terminal region was anchored onto a solid phase. Together with the finding that helix C is involved in the self-association of Hsp70, our present data suggest that the C-terminal region of Hsp70 modulates the substrate recognition and its kinetics may be substrate-mass dependent.
Ohno
Michiko
M
Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Goka-sho, Uji, Kyoto 611-0011, Japan.
Kitabatake
Naofumi
N
Tani
Fumito
F
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D018833:Chaperonins / Q000737:chemistry / Q000378:metabolism; D002850:Chromatography, Gel; D017931:DNA Primers; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000378:metabolism*; D007768:Lactalbumin / Q000378:metabolism; D051379:Mice; D008958:Models, Molecular; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D017384:Sequence Deletion; D013816:Thermodynamics
D017931:DNA Primers; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D011994:Recombinant Proteins; D007768:Lactalbumin; D018833:Chaperonins