title: MAD2B is an inhibitor of the anaphase-promoting complex.
abstract: Anaphase-promoting complex (APC), a ubiquitin ligase, controls both sister chromatid separation and mitotic exit. The APC is activated in mitosis and G1 by CDC20 and CDH1, and inhibited by the checkpoint protein MAD2, a specific inhibitor of CDC20. We show here that a MAD2 homolog MAD2B also inhibits APC. In contrast to MAD2, MAD2B inhibits both CDH1-APC and CDC20-APC. This inhibition is targeted to CDH1 and CDC20, but not directly to APC. Unlike MAD2, whose interaction with MAD1 is required for mitotic checkpoint control, MAD2B does not interact with MAD1, suggesting that MAD2B may relay a different cellular signal to APC.
authors.affiliation: Department of Biological Sciences, Stanford University, Stanford, California 94305-5020, USA.
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: G
authors.initials: G
authors.lastname: Fang
mesh_terms: D064173:Anaphase-Promoting Complex-Cyclosome; D000818:Animals; D064199:Cdc20 Proteins; D018797:Cell Cycle Proteins / Q000378:metabolism; D002842:Chromatids / Q000502:physiology; D003001:Cloning, Molecular; D019926:Cyclin B / Q000378:metabolism; D006801:Humans; D008025:Ligases / Q000037:antagonists & inhibitors*; D064246:Mad2 Proteins; D008938:Mitosis / Q000502:physiology*; D009687:Nuclear Proteins; D010750:Phosphoproteins / Q000378:metabolism; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D013347:Subcellular Fractions / Q000378:metabolism; D043743:Ubiquitin-Protein Ligase Complexes; D044767:Ubiquitin-Protein Ligases; D014981:Xenopus
chemical_list: C577495:CDC20 protein, S cerevisiae; D064199:Cdc20 Proteins; D018797:Cell Cycle Proteins; D019926:Cyclin B; C501382:MAD1 protein, S cerevisiae; C501384:MAD1L1 protein, human; C120552:MAD2L2 protein, human; D064246:Mad2 Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; D011506:Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D043743:Ubiquitin-Protein Ligase Complexes; D064173:Anaphase-Promoting Complex-Cyclosome; D044767:Ubiquitin-Protein Ligases; D008025:Ligases