The molecular mechanism of CUL4B E3 ubiquitin ligase complex by SIRT7

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K21238
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Pathological medical chemistry; General medical chemistry
• Research Institution: Kumamoto University
• Principal Investigator: Karim Md. Fazlul 熊本大学, 大学院生命科学研究部(医), 助教 (10746316)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: サーチュイン / SIRT7 / ユビキチンリガーゼ複合体 / DDB1

Outline of Final Research Achievements

SIRT7 is an NAD dependent deacetylase. We found that SIRT7 increases the hepatic lipid accumulation by inhibiting the degradation of TR4, a nuclear receptor that plays a critical role in lipid homeostasis, via the DCAF1/DDB1/CUL4B E3 ubiquitin ligase complex. In the present study, we identified that SIRT7 interacts with in vitro translated DDB1. Interaction of SIRT7 and DDB1 was also detected in cultured 293T cells by the co-immunoprecipitation assay. Furthermore, SIRT7 reduced acetylation of DDB1. These results suggest that SIRT7 regulates DCAF1/DDB1/CUL4B E3 ubiquitin ligase complex via DDB1 deacetylation. Further studies are necessary to the functional consequence of DDB1 deacetylation in the DCAF1/DDB1/CUL4B E3 ubiquitin ligase complex.

Free Research Field

生化学