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|
| Type |
Poster Presentation |
| Area |
Life Chemistry |
| Room No. |
Exhibition Hall 2+3 |
| Time |
10월 19일 (목요일) 11:00~12:30 |
| Code |
BIO.P-250 |
| Subject |
Cyclophilins protect yeast cells from freeze-stress |
| Authors |
Hana Im*, SeungHyun Lee
Department of Integrative Bioscience and Biotechnology, Sejong University, Korea
|
| Abstract |
Exposure to freezing temperatures are one of the major challenges faced by many organisms. Low temperatures reduces protein folding rates and induces the cold denaturation of proteins, necessitating aid from chaperones. Thus, a yeast ORF-deletion library lacking individual chaperones were screened for reduced freezing tolerance. In total, 19 of 82 chaperone-deleted strains tested were more sensitive to freeze–thaw treatment than wild-type cells. The freeze survival of the chaperone-knockout strains was increased in the presence of 20% glycerol, suggesting that ice crystal formation during freezing may be one of the major causes of cell death. Among those, peptidyl-prolyl cis-trans isomerases (PPIases) including cyclophilins, were the most frequently identified. At low temperatures, peptidyl-prolyl isomerization is a rate-limiting step in protein folding, and folding intermediates, which are prone to protein aggregation, tend to accumulate. Overexpression of PPIases protected β-galactosidase protein from cold denaturation. Purified PPIases also facilitated the refolding of a slow-folding substrate protein in vitro. These results suggest that the identified PPIases enhance cold survival of cells by preventing cold-induced protein denaturation and promoting protein folding.
This work was supported by grants from the National Research Foundation of Korea (KRF-2015R1D1A1 A01058206). |
| E-mail |
hanaim@sejong.ac.kr |
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120th General Meeting of the KCS