CLONING AND EXPRESSION OF MYELIN-ASSOCIATED OLIGODENDROCYTIC BASIC-PROTEIN - A NOVEL BASIC-PROTEIN CONSTITUTING THE CENTRAL-NERVOUS-SYSTEM MYELIN

We have screened genes predominantly expressed in the rat spinal cord, and we report here cloning of the most abundant unknown gene. It is a novel member of the central nervous system (CNS) myelin constituting proteins, myelin-associated oligodendrocytic basic protein (MOBP), MOB P is abundantly expressed specifically in oligodendrocytes at the mRNA level only next to myelin basic protein (MBP) and proteolipid protein . Two isoforms have been confirmed. One of them has proline-rich tande m repeats and has 84% homology with human counterpart in terms of pred icted amino acid sequences. The cDNA-derived primary structure predict s a small, soluble, basic protein The immunoelectron tron microscopy h as shown that MOBP is expressed throughout compact myelin. All these c haracteristics are similar to MBP. One definite difference between MBP and MOBP is that MOBP is expressed exclusively in the CNS myelin. The se findings suggest that MOBP shares some important functions with MBP in the CNS myelin such as myelin compaction.