Neuronal migration VLDL receptor

organization of 6 layered neocortex. in absence of vldlr, neuroblasts of cortical plate invade marginal zone above.

vldlr responsible correct layering of pyramidal cells layer 1 of cerebral cortex. in particular, absence of vldlr may lead ectopic accumulation of pyramidal cells in region. vldlr not affect migration of born cells organized layer, since absence results in invasion of these neuroblasts marginal zone, theorized vldlr may encode “stop signal.” supported fact vldlr expressed in cortical plate adjacent reelin-expressing cells, cajal–retzius cells, , in intermediate zone. however, definitive evidence has not yet been found. in general, reelin binds vldlr , undergoes endocytosis via clathrin-coated vesicles. meanwhile, intracellular protein, dab1, has pi/ptb domain interacts npxy sequence found in cytoplasmic tail of vldlr. result, dab1 tyrosine phosphorylated , reelin degraded. finally, phosphorylated dab1 activates intracellular signaling cascade directs neuroblasts proper location through alteration of cytoskeleton. many of specifics of pathway still being investigated. not yet known if dab1 phosphorylated result of endocytosis of reelin, or if there mechanism @ play. in addition organization of neocortex, vldlr plays role in neuronal migration of hippocampus , purkinje cells of cerebellum. yet, information on process still unknown.