Small-number issues in biological rhythms: regulation of oscillation system with low-abundant proteins through tuning turnover rate

2015 Fiscal Year Final Research Report

• Project Area: Spying minority in biological phenomena -Toward bridging dynamics between individual and ensemble processes-
• Project/Area Number: 23115006
• 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: The University of Tokyo (2013-2015); The Institute of Physical and Chemical Research (2011-2012)
• Principal Investigator: UEDA Hiroki 東京大学, 医学(系)研究科(研究院), 教授 (20373277)
• Co-Investigator(Kenkyū-buntansha): ODE Koji 東京大学, 大学院医学系研究科, 助教 (40612122) ; UKAI Hideki 理化学研究所, 生命システム研究センター, 上級研究員 (70391878) ; NAKAJIMA Masato 近畿大学, 医学部, 助教 (50432232)
• Research Collaborator: UKAI Hideki 理化学研究所, 生命システム研究センター, 上級研究員 (70391878)
• Project Period (FY): 2011-04-01 – 2016-03-31
• Keywords: 概日時計 / 質量分析 / 絶対定量 / ターンオーバーレート / 分子少数性

Outline of Final Research Achievements

Previous studies suggest that the expression level of circadian core factors, most of them work as transcription regulators are generally low. In this project, we carried out absolute quantification of circadian core transcription factors throughout the various circadian time points, and revealed that the expression amount varies between 1,000 ~ 20,000 molecules / cell, the concentration range lower than the expression level of most proteins in cell. We then asked the mechanism, by which circadian transcription factors at low expression level ensures rhythmic transcription oscillation with precise 24 hour period. We found that CRY, a core component of circadian transcription factors regulates circadian period through amount regulation depending on the turnover rate of CRY protein and state regulation depending on the phosphorylation status of the protein.

Free Research Field

システム生物学