Contribution of the C-Terminal Region of a Group II Chaperonin to its Interaction with Prefoldin and Substrate Transfer
| Autor: | Muhamad Sahlan, Masafumi Yohda, Tamotsu Zako, Sayaka Fujii, Mizuo Maeda, Yohei Y. Yamamoto, Kotaro Sakai |
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| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Protein Denaturation Protein Folding Green Fluorescent Proteins Mutant Group II Chaperonins Citrate (si)-Synthase Plasma protein binding Protein aggregation Green fluorescent protein Chaperonin Protein Aggregates 03 medical and health sciences Structural Biology Molecular Biology biology Prefoldin 030104 developmental biology Biochemistry Chaperone (protein) Mutation biology.protein Biophysics Protein folding Molecular Chaperones Protein Binding |
| Zdroj: | Journal of Molecular Biology. 428:2405-2417 |
| ISSN: | 0022-2836 |
| DOI: | 10.1016/j.jmb.2016.04.006 |
| Popis: | Prefoldin is a molecular chaperone that captures an unfolded protein substrate and transfers it to a group II chaperonin. Previous studies have shown that the interaction sites for prefoldin are located in the helical protrusions of group II chaperonins. However, it does not exclude the possibility of the existence of other interaction sites. In this study, we constructed C-terminal truncation mutants of a group II chaperonin and examined the effects of these mutations on the chaperone's function and interaction with prefoldin. Whereas the mutants with up to 6 aa truncation from the C-terminus retained more than 90% chaperone activities for protecting citrate synthase from thermal aggregation and refolding of green fluorescent protein and isopropylmalate dehydrogenase, the truncation mutants showed decreased affinities for prefoldin. Consequently, the truncation mutants showed reduced transfer efficiency of the denatured substrate protein from prefoldin and subsequent chaperonin-dependent refolding. The results clearly show that the C-terminal region of group II chaperonins contributes to their interactions with prefoldin, the transfer of the substrate protein from prefoldin and its refolding. |
| Databáze: | OpenAIRE |
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