Functional cooperation between FACT and MCM is coordinated with cell cycle and differential complex formation

Journal of Biomedical Science

Research

Bertrand Chin-Ming Tan¹  Chih-Li Lin¹  Hsuan Liu¹  Sheng-Chung Lee² 

[1] Department of Life Science, College of Medicine, Chang Gung Univeristy, Taoyuan, Taiwan;Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan;Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan;

关键词: Helicase Activity;    Sodium Butyrate;    Origin Recognition Complex;    Origin Binding;    Helicase Assay;   

DOI  :  10.1186/1423-0127-17-11

 received in 2009-11-17, accepted in 2010-02-16,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundFunctional cooperation between FACT and the MCM helicase complex constitutes an integral step during DNA replication initiation. However, mode of regulation that underlies the proper functional interaction of FACT and MCM is poorly understood.Methods & ResultsHere we present evidence indicating that such interaction is coordinated with cell cycle progression and differential complex formation. We first demonstrate the existence of two distinct FACT-MCM subassemblies, FACT-MCM2/4/6/7 and FACT-MCM2/3/4/5. Both complexes possess DNA unwinding activity and are subject to cell cycle-dependent enzymatic regulation. Interestingly, analysis of functional attributes further suggests that they act at distinct, and possibly sequential, steps during origin establishment and replication initiation. Moreover, we show that the phosphorylation profile of the FACT-associated MCM4 undergoes a cell cycle-dependent change, which is directly correlated with the catalytic activity of the FACT-MCM helicase complexes. Finally, at the quaternary structure level, physical interaction between FACT and MCM complexes is generally dependent on persistent cell cycle and further stabilized upon S phase entry. Cessation of mitotic cycle destabilizes the complex formation and likely leads to compromised coordination and activities.ConclusionsTogether, our results correlate FACT-MCM functionally and temporally with S phase and DNA replication. They further demonstrate that enzymatic activities intrinsically important for DNA replication are tightly controlled at various levels, thereby ensuring proper progression of, as well as exit from, the cell cycle and ultimately euploid gene balance.

【 授权许可】

CC BY   
© Tan et al; licensee BioMed Central Ltd. 2010