Mitotic spindle assembly checkpoint, MAD1-MAD2 complex Overview

GO Annotations consist of four mandatory components: a gene product, a term from one of the three Gene Ontology (GO) controlled vocabularies (Molecular Function, Biological Process, and Cellular Component), a reference, and an evidence code.

Summary

Acts at the spindle checkpoint, in a surveillance mechanism that mediates a delay in the onset of anaphase, until all chromosomes are properly attached to the mitotic or meiotic spindle. Required for the checkpoint response to absence of spindle tension, localising only to unattached kinetochores but not to attached kinetochores that lack tension, and participate in a bipolar orientation defect signaling pathway. MAD2 adopts two distinct conformations; when unbound, it adopts an open conformation (O-Mad2) but upon binding to MAD1 (or CDC20, P26309), two beta-sheets move across the face of the protein to create the closed conformation (C-Mad2), with MAD1 now trapped within this fold. Upon mitotic entry, the Mad1-C-Mad2 core complex is recruited to kinetochores. Because Mad2 can dimerise, O-Mad2 from the cytosol can then be recruited to kinetochore-bound Mad1-C-Mad2. C-Mad2 within the Mad1-C-Mad2 core complex acts as a prion-like template, catalysing the conversion of additional O-Mad2 proteins to the closed conformation and in doing so binding Cdc20 (CPX-962).

GO Slim Terms

The yeast GO Slim terms are higher level terms that best represent the major S. cerevisiae biological processes, functions, and cellular components. The GO Slim terms listed here are the broader parent terms for the specific terms to which this gene product is annotated, and thus represent the more general processes, functions, and components in which it is involved.

regulation of cell cycle, regulation of organelle organization, signal transduction, organelle, intracellular non-membrane-bounded organelle, kinetochore

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