期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2010
卷号：107
期号：7
页码：2932-2937
DOI：10.1073/pnas.0914874107
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Centrosomes have recently emerged as key regulators of the cell cycle. The G1/S transition requires a functional centrosome, and centrosomal localization of numerous proteins, including cyclin/Cdk complexes, is important for the G2/M transition. Here we identify a modular centrosomal localization signal (CLS) localizing cyclin A to centrosomes independently of Cdk binding. The cyclin A CLS is located in a distinct part of the molecule compared with the cyclin E CLS and includes the MRAIL hydrophobic patch involved in substrate recognition. The cyclin A CLS interacts with p27KIP1, and expression of p27KIP1 removes cyclin A but not cyclin E from centrosomes. Expression of the cyclin A CLS displaces both endogenous cyclin A and E from centrosomes and inhibits DNA replication, supporting an emerging concept that DNA replication is linked to centrosomal events. Structural analysis indicates that differences in surface charge and length of the C-terminal helix explain why the MRAIL region in cyclin E is not a functional CLS. These results indicate that the cyclin A CLS may contribute to targeting and recognition of centrosomal Cdk substrates and is required for specific effects of p27KIP1 on cyclin A-Cdk2.
