Analysis of Hsk1 function in genome dynamics regulation by using new Hsk1-bypass mutants

2014 Fiscal Year Final Research Report

• Project/Area Number: 24570205
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Molecular biology
• Research Institution: Tokyo Metropolitan Institute of Medical Science
• Principal Investigator: MATSUMOTO Seiji 公益財団法人東京都医学総合研究所, ゲノム医科学研究分野, 主任研究員 (40190532)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: DNA複製 / 複製タイミング / CDC7 / hsk1 / mrc1 / rif1

Outline of Final Research Achievements

mrc1Δ and rif1Δ can bypass the requirement of Hsk1 kinase. mrc1-3A, specifically defective in checkpoint, and mrc1ΔHBS (Δ782-879), proficient in checkpoint, can independently rescue hsk1ts, albeit less efficiently, and combination of mrc1-3A and mrc1ΔHBS rescues hsk1ts almost as efficiently as mrc1Δ, confirming that mrc1Δ can bypass Hsk1 in both checkpoint-dependent and -independent manners. Initiation of DNA replication is enhanced at early origins in ΔHBS. C-terminus (781-1019) of Mrc1 containing HBS can interact with the N-terminus and inhibits the mrc1ΔHBS-mediated bypass of hsk1ts. Intramolecular interaction between C-terminus and N-terminus renders Mrc1 in an inhibitory conformation, and phosphorylation through HBS causes dissociation of the N-terminal segment from the C-terminus, transforming Mrc1 into a permissive conformation that can rescue hsk1ts. We found a consensus sequence among Rif1-binding regions which is essential for Rif1 to regulate initiation.

Free Research Field

分子生物学・細胞生物学、生物科学・分子生物学