The Spindly–dynein–dynactin complex binds to the RZZ complex and initiates the disassembly of the fibrous corona and removal of checkpoint proteins upon kinetochore–microtubule attachment. (A) At unattached kinetochores, binding of the KMN network to microtubules is inhibited by the presence of the RZZ complex and by Aurora B kinase phosphorylation. The RZZ complex self-assembles into the fibrous corona and recruits the spindle checkpoint proteins Mad1/Mad2 and Spindly, which in turn recruit dynein. (B) Upon stabilization of a kinetochore–microtubule attachment, the Spindly–dynein–dynactin complex walks to the minus end of microtubules with its RZZ and spindle checkpoint cargo. Thus, dynein disassembles the fibrous corona and silences the spindle checkpoint by “stripping” the checkpoint proteins away from the outer kinetochore.