Cortical cytoskeleton protein found in a complex involved in maintaining cell polarity and epithelial integrity. Involved in the regulation of mitotic spindle orientation, proliferation, differentiation and tissue organization of neuroepithelial cells. Involved in axonogenesis through RAB10 activation thereby regulating vesicular membrane trafficking toward the axonal plasma membrane (By similarity). Associated with nonmuscle myosin II heavy chain. Interacts with PRKCI/aPKC, PARD6B/Par-6 and PARD6A. Interacts with STX4A. Interacts with RAB10 (GDP-bound form); the interaction is direct and promotes RAB10 association with membranes and activation through competition with the Rab inhibitor GDI1. Interacts with DCAF1 (By similarity). Localized to the lateral membrane during the polarization and formation cell-cell contacts. Enriched in developing axons (By similarity). Widely expressed. Expressed in brain, ovary, testis, with moderate expression in lever, uterus, lung and kidney. Phosphorylated by PRKCI. Complements a salt-sensitive yeast mutant (SOP-deleted mutant) and thus can regulate cation homeostasis. Belongs to the WD repeat L(2)GL family.