THE HUMAN GENE CGT ENCODING THE UDP-GALACTOSE CERAMIDE CALACTOSYL TRANSFERASE (CEREBROSIDE SYNTHASE) - CLONING, CHARACTERIZATION, AND ASSIGNMENT TO HUMAN-CHROMOSOME-4, BAND Q26

We have previously cloned the human UDP-galactose ceramide galactosylt ransferase (CGT, E.C. 2.4.1.45) cDNA. Its open reading frame encodes t he key enzyme in the biosynthesis of the glycosphingolipids, cerebrosi des and sulfatides, essential constituents of the myelin membrane of t he central nervous system (CNS) and PNS. Expression of the CGT gene an d of the myelin-specific proteins in the terminal differentiated oligo dendrocyte of CNS and in Schwann cells of PNS is cell-specific and hig hly time-regulated. The CGT gene therefore is important in the differe ntiation program of the oligodendrocyte lineage. Here we report the st ructural organization and the chromosomal localization of the human CG T gene. The coding sequence is separated into five exons, which are di stributed over >40 kb. The CGT locus was mapped to the distal region o f human chromosome 4, band q26. The organization of the CGT gene and o f the UGT (uridylglucuronosyltransferases) gene family suggests a corr elation to functional domains of the encoded proteins. (C) 1996 Academ ic Press, Inc.