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. Dimerization mediated by the LisH domain may be required to activate dynein. Belongs to the WD repeat LIS1/nudF family.