Eb1 Proteins Regulate Microtubule Dynamics, Cell Polarity, and Chromosome Stability

The EB1 family represents a highly conserved group of proteins, present in yeast through humans, that localize to spindle and cytoplasmic microtubules, especially at their distal tips. The budding yeast homologue of EB1, Bim1p, regulates microtubule stability and is important for positioning the mitotic spindle, anchoring it to the bud through astral microtubule attachment to the cortical protein Kar9p. Bim1p interacts functionally with dynactin in a late mitotic cell cycle checkpoint. EB1 proteins in human cells interact physically with the adenomatous polyposis coli (APC) tumor suppressor protein, targeting APC to microtubule plus ends, and with members of the dynactin complex. Here, we review recent studies in yeast and human cells that suggest the involvement of EB1 in promoting microtubule search and capture and in maintaining chromosome stability.