Under normal circumstances, the SAC monitors the attachment of kinetochores to spindle microtubules. This monitoring is facilitated by several key proteins, including Mad1, Mad2, Bub1, BubR1, and Mps1. When errors are detected, these proteins inhibit the anaphase-promoting complex/cyclosome (APC/C), thereby delaying the onset of anaphase until all chromosomes are correctly attached.
