Plays a role in mitotic bipolar spindle formation. Binds mRNA. May function in nucleocytoplasmic transport and in directly or indirectly attaching cytoplasmic mRNPs to the cytoskeleton. Interacts with NUMA1 (via N-terminal end of the coiled-coil domain); this interaction promotes spindle formation in mitosis (By similarity). Interacts with NUP98 (PubMed:10209021). Interacts with MYCBP2 (By similarity). Interacts with USP11 (By similarity). Recruited from interphase nuclei to spindle MTs during mitosis. Belongs to the WD repeat rae1 family.