Structural Basis for Chk1 Inhibition by UCN-01

作者：Baoguang Zhao, Michael J. Bower, Patrick McDevitt, Huizhen Zhao, Stephen T. Davis, Kyung Johanson, Susan M. Green, N.O. Concha, Bin‐Bing S. Zhou · 发表于：Journal of Biological Chemistry · 年份：2002 · DOI：10.1074/jbc.m201233200 · 被引用次数：207 · 研究领域：DNA Repair Mechanisms、Carcinogens and Genotoxicity Assessment、Cancer-related Molecular Pathways

Chk1 is a serine-threonine kinase that plays an important role in the DNA damage response, including G(2)/M cell cycle control. UCN-01 (7-hydroxystaurosporine), currently in clinical trials, has recently been shown to be a potent Chk1 inhibitor that abrogates the G(2)/M checkpoint induced by DNA-damaging agents. To understand the structural basis of Chk1 inhibition by UCN-01, we determined the crystal structure of the Chk1 kinase domain in complex with UCN-01. Chk1 structures with staurosporine and its analog SB-218078 were also determined. All three compounds bind in the ATP-binding pocket of Chk1, producing only slight changes in the protein conformation. Selectivity of UCN-01 toward Chk1 over cyclin-dependent kinases can be explained by the presence of a hydroxyl group in the lactam moiety interacting with the ATP-binding pocket. Hydrophobic interactions and hydrogen-bonding interactions were observed in the structures between UCN-01 and the Chk1 kinase domain. The high structural complementarity of these interactions is consistent with the potency and selectivity of UCN-01.