Essential subunit of the Dam1 complex (aka DASH complex); cooperates with Duo1p and Pse1p to connect the DASH complex with the microtubules (MT); couples kinetochores to the force produced by MT depolymerization, thereby aiding in chromosome segregation; N-terminal staple region is important for self-assembly of the Dam1 complex higher order ring structure that forms around microtubules; Ipl1p target for regulating kinetochore-MT attachments