Neuronal expression of the ERM-like protein MIR in rat brain and its localization to human chromosome 6

The ERM proteins, ezrin, radixin, and moesin, regulate cell motility by lin king cortical F-actin to the plasma membrane in different cell types. Myosi n regulatory light chain interacting protein (MIR) is a recently cloned ERM -like protein which was shown to be involved in neurite outgrowth. Here we have studied the occurrence and expression of MIR in rats during brain deve lopment. As Shown using Western blotting, MIR is present in different regio ns both in developing and adult brain, Immunohistochemistry and double labe lling studies showed that MIR is localized especially to neurons in hippoca mpus and cerebellum. A search using the gene bank showed that the MIR gene localised to human chromosome 6 in the interval 6p22.3-23, the loss of whic h is characterized by mental retardation and different malformations in man . The presence of MIR in brain neurons during development together with its known effects on neurite outgrowth suggest an important function of the pr otein in the regulation of nerve cell motility and cytoskeletal interaction s. (C) 2000 Academic Press.