title: Cdh1 is an antagonist of the spindle assembly checkpoint.
abstract: The spindle assembly checkpoint (SAC) monitors unsatisfied connections of microtubules to kinetochores and prevents anaphase onset by inhibition of the ubiquitin ligase E3 anaphase-promoting complex or cyclosome (APC/C) in association with the activator Cdc20. Another APC/C activator, Cdh1, exists permanently throughout the cell cycle but it becomes active from telophase to G1. Here, we show that Cdh1 is partially active and mediates securin degradation even in SAC-active metaphase cells. Additionally, Cdh1 mediates Cdc20 degradation in metaphase, promoting formation of the APC/C-Cdh1. These results indicate that Cdh1 opposes the SAC and promotes anaphase transition.
authors.affiliation: Department of Biological Science, Faculty of Science, Shizuoka University, Shizuoka 422-8529, Japan.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Nagai
authors.affiliation: Department of Biological Science, Faculty of Science, Shizuoka University, Shizuoka 422-8529, Japan. Electronic address: sbtushi@ipc.shizuoka.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ushimaru
mesh_terms: D000705:Anaphase; D064173:Anaphase-Promoting Complex-Cyclosome / Q000378:metabolism; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D064199:Cdc20 Proteins / Q000378:metabolism; D059566:M Phase Cell Cycle Checkpoints; D008677:Metaphase; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D064249:Securin / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D015820:Cadherins; D064199:Cdc20 Proteins; D029701:Saccharomyces cerevisiae Proteins; D064249:Securin; D064173:Anaphase-Promoting Complex-Cyclosome
keywords: Anaphase-promoting complex or cyclosome (APC/C); Cdc20; Cdh1; Saccharomyces cerevisiae; Spindle assembly checkpoint (SAC)