Positively regulates the activity of the minus-end directed microtubule motor protein dynein. Plays a central role in positioning the mitotic spindle at the bud neck during cell division. Targets cytoplasmic dynein to microtubule plus ends, thereby promoting dynein-mediated microtubule sliding along the bud cortex and consequently the movement of the mitotic spindle to the bud neck. Self-associates. Interacts with NDL1 and dynein. Localizes to the plus ends of microtubules and the mitotic spindle poles. Belongs to the WD repeat LIS1/nudF family.