Involved in microtubule polymerization, and spindle function by stabilizing microtubules and anchoring them at centrosomes. Interacts with mtaA/CP224 at the microtubule tip, centrosome and kinetochore. Associated with the microtubule network. Accumulates at the plus end of microtubules. Defects in cytokinesis due to poor mitotic spindle assembly during mitotic prometaphase. Belongs to the MAPRE family.