An oligodendrocyte enhancer in a phylogenetically conserved intron region of the mammalian myelin gene Opalin.
Opalin is a transmembrane protein detected specifically in mammalian oligodendrocytes. Opalin homologs are found only in mammals and not in the genome sequences of other animal classes. We first determined the nucleotide sequences of Opalin orthologs and their flanking regions derived from four prosimians, a group of primitive primates. A global comparison revealed that an evolutionarily conserved region exists in the first intron of Opalin. When the conserved domain was assayed for its enhancer activity in transgenic mice, oligodendrocyte-directed expression was observed. In an oligodendroglial cell line, Oli-neu, the conserved domain showed oligodendrocyte-directed expression. The conserved domain is composed of eight subdomains, some of which contain binding sites for Myt1 and cAMP-response element binding protein (CREB). Deletion analysis and cotransfection experiments revealed that the subdomains have critical roles in Opalin gene expression. Over-expression of Myt1, treatment of the cell with leukemia inhibitory factor (LIF), and cAMP analog (CREB activator) enhanced the expression of endogenous Opalin in Oli-neu cells and activated the oligodendrocyte enhancer. These results suggest that LIF, cAMP signaling cascades and Myt1 play significant roles in the differentiation of oligodendrocytes through their action on the Opalin oligodendrocyte enhancer.
Aruga
Jun
J
Laboratory for Comparative Neurogenesis, RIKEN Brain Science Institute, Wako-shi, Saitama, JapanLaboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Wako-shi, Saitama, JapanSequence Technology Team, RIKEN Genomic Science Center, Yokohama, Japan.
Yoshikawa
Fumio
F
Laboratory for Comparative Neurogenesis, RIKEN Brain Science Institute, Wako-shi, Saitama, JapanLaboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Wako-shi, Saitama, JapanSequence Technology Team, RIKEN Genomic Science Center, Yokohama, Japan.
Nozaki
Yayoi
Y
Laboratory for Comparative Neurogenesis, RIKEN Brain Science Institute, Wako-shi, Saitama, JapanLaboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Wako-shi, Saitama, JapanSequence Technology Team, RIKEN Genomic Science Center, Yokohama, Japan.
Sakaki
Yoshiyuki
Y
Laboratory for Comparative Neurogenesis, RIKEN Brain Science Institute, Wako-shi, Saitama, JapanLaboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Wako-shi, Saitama, JapanSequence Technology Team, RIKEN Genomic Science Center, Yokohama, Japan.
Toyoda
Atsushi
A
Laboratory for Comparative Neurogenesis, RIKEN Brain Science Institute, Wako-shi, Saitama, JapanLaboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Wako-shi, Saitama, JapanSequence Technology Team, RIKEN Genomic Science Center, Yokohama, Japan.
Furuichi
Teiichi
T
Laboratory for Comparative Neurogenesis, RIKEN Brain Science Institute, Wako-shi, Saitama, JapanLaboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Wako-shi, Saitama, JapanSequence Technology Team, RIKEN Genomic Science Center, Yokohama, Japan.
D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D003001:Cloning, Molecular; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D023281:Genomics; D006801:Humans; D007438:Introns / Q000502:physiology*; D053605:Leukemia Inhibitory Factor / Q000494:pharmacology; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D009185:Myelin Proteins / Q000235:genetics* / Q000378:metabolism*; D009836:Oligodendroglia / Q000187:drug effects / Q000502:physiology*; D010802:Phylogeny; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000502:physiology*; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D011443:Strepsirhini; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014162:Transfection
D017362:Cyclic AMP Response Element-Binding Protein; D004268:DNA-Binding Proteins; D053605:Leukemia Inhibitory Factor; D008156:Luciferases; D009185:Myelin Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; C489726:Myt1 protein, mouse; C524020:OPALIN protein, human; C524019:Opalin protein, mouse