Inhibition of the anaphase-promoting complex by the Xnf7 ubiquitin ligase.
Journal Article (Journal Article)
Degradation of specific protein substrates by the anaphase-promoting complex/cyclosome (APC) is critical for mitotic exit. We have identified the protein Xenopus nuclear factor 7 (Xnf7) as a novel APC inhibitor able to regulate the timing of exit from mitosis. Immunodepletion of Xnf7 from Xenopus laevis egg extracts accelerated the degradation of APC substrates cyclin B1, cyclin B2, and securin upon release from cytostatic factor arrest, whereas excess Xnf7 inhibited APC activity. Interestingly, Xnf7 exhibited intrinsic ubiquitin ligase activity, and this activity was required for APC inhibition. Unlike other reported APC inhibitors, Xnf7 did not associate with Cdc20, but rather bound directly to core subunits of the APC. Furthermore, Xnf7 was required for spindle assembly checkpoint function in egg extracts. These data suggest that Xnf7 is an APC inhibitor able to link spindle status to the APC through direct association with APC core components.
Full Text
Duke Authors
Cited Authors
- Casaletto, JB; Nutt, LK; Wu, Q; Moore, JD; Etkin, LD; Jackson, PK; Hunt, T; Kornbluth, S
Published Date
- April 2005
Published In
Volume / Issue
- 169 / 1
Start / End Page
- 61 - 71
PubMed ID
- 15824132
Pubmed Central ID
- PMC2171901
Electronic International Standard Serial Number (EISSN)
- 1540-8140
International Standard Serial Number (ISSN)
- 0021-9525
Digital Object Identifier (DOI)
- 10.1083/jcb.200411056
Language
- eng