Development of biochemical methods to understand protein ubiquitylation

2016 Fiscal Year Final Research Report

• Project Area: New aspect of the ubiquitin system : its enormous roles in protein regulation
• Project/Area Number: 24112008
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Biological Sciences
• Research Institution: Tokyo Metropolitan Institute of Medical Science
• Principal Investigator: SAEKI Yasushi 公益財団法人東京都医学総合研究所, 生体分子先端研究分野, 副参事研究員 (80462779)
• Project Period (FY): 2012-06-28 – 2017-03-31
• Keywords: 細胞内タンパク質分解 / ユビキチン / プロテアソーム / 質量分析計

Outline of Final Research Achievements

Ubiquitylation is a post-translational modification that regulates numerous important cellular processes including proteasomal degradation, DNA repair, protein sorting, and signal transduction. The diverse functions of ubiquitin depend on the ubiquitin chain topology with eight linkage types, lengths, chemical modifications, and their combinations. To clarify the ubiquitin code, we developed an ultra-sensitive absolute quantification method of ubiquitin chains and a comprehensive identification method of ubiquitylated substrates using a high resolution mass spectrometry. Then, we applied them to the analysis of various important substrates found in the research group. In addition, we comprehensively analyzed ubiquitin chain type selectivity of yeast ubiquitin-binding proteins and found that proteasomal degradation is predominantly regulated by the Cdc48-Rad23/Dsk2 axis. Thus, we provided the first overall picture of the ubiquitin network via ubiquitin-binding proteins.

Free Research Field

生化学