title: Co-activator independent differences in how the metaphase and anaphase APC/C recognise the same substrate.
abstract: The Anaphase Promoting Complex or Cyclosome (APC/C) is critical to the control of mitosis. The APC/C is an ubiquitin ligase that targets specific mitotic regulators for proteolysis at distinct times in mitosis, but how this is achieved is not well understood. We have addressed this question by determining whether the same substrate, cyclin B1, is recognised in the same way by the APC/C at different times in mitosis. Unexpectedly, we find that distinct but overlapping motifs in cyclin B1 are recognised by the APC/C in metaphase compared with anaphase, and this does not depend on the exchange of Cdc20 for Cdh1. Thus, changes in APC/C substrate specificity in mitosis can potentially be conferred by altering interaction sites in addition to exchanging Cdc20 for Cdh1.
authors.affiliation: The Gurdon Institute, Tennis Court Road, Cambridge CB2 1QN, UK Department of Zoology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Matsusaka
authors.affiliation: Department of Physiology, University of California in San Francisco (UCSF), 600 16th Street, San Francisco, CA 94158, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Enquist-Newman
authors.affiliation: Department of Physiology, University of California in San Francisco (UCSF), 600 16th Street, San Francisco, CA 94158, USA.
authors.forename: David O
authors.initials: DO
authors.lastname: Morgan
authors.affiliation: The Gurdon Institute, Tennis Court Road, Cambridge CB2 1QN, UK Department of Zoology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK jp103@cam.ac.uk.
authors.forename: Jonathon
authors.initials: J
authors.lastname: Pines
keywords: Anaphase Promoting Complex/Cyclosome; Cyclin B; Mitosis