Identification of the nuclear localization signal in Xenopus cyclin E and analysis of its role in replication and mitosis.
Journal Article (Journal Article)
Cyclin-dependent kinase (Cdk)2/cyclin E is imported into nuclei assembled in Xenopus egg extracts by a pathway that requires importin-alpha and -beta. Here, we identify a basic nuclear localization sequence (NLS) in the N-terminus of Xenopus cyclin E. Mutation of the NLS eliminated nuclear accumulation of both cyclin E and Cdk2, and such versions of cyclin E were unable to trigger DNA replication. Addition of a heterologous NLS from SV40 large T antigen restored both nuclear targeting of Cdk2/cyclin E and DNA replication. We present evidence indicating that Cdk2/cyclin E complexes must become highly concentrated within nuclei to support replication and find that cyclin A can trigger replication at much lower intranuclear concentrations. We confirmed that depletion of endogenous cyclin E increases the concentration of cyclin B necessary to promote entry into mitosis. In contrast to its inability to promote DNA replication, cyclin E lacking its NLS was able to cooperate with cyclin B in promoting mitotic entry.
Full Text
Duke Authors
Cited Authors
- Moore, JD; Kornbluth, S; Hunt, T
Published Date
- December 2002
Published In
Volume / Issue
- 13 / 12
Start / End Page
- 4388 - 4400
PubMed ID
- 12475960
Pubmed Central ID
- PMC138641
Electronic International Standard Serial Number (EISSN)
- 1939-4586
International Standard Serial Number (ISSN)
- 1059-1524
Digital Object Identifier (DOI)
- 10.1091/mbc.e02-07-0449
Language
- eng