Molecular cloning of a novel transmembrane protein MOLT expressed by mature oligodendrocytes.
A novel oligodendrocyte (OL)-specific cDNA was isolated from brain capillary endothelial cells and characterized. The cDNA encodes a protein of 1099 amino acids that contains a signal peptide and a transmembrane domain. The protein was expressed in mature OLs in vivo and in vitro cell cultures and was thus designated as mature OL transmembrane protein (MOLT). RT-PCR analysis showed that MOLT mRNA was expressed in brain, lung, pancreas, and testis. A polyclonal antibody raised against a part of the mouse MOLT reacted specifically with multipolar OLs possessing radially oriented processes that penetrated into the gray matter. More cells were detected in the white matter, and these had longitudinally oriented processes. In a rat OL lineage culture system, oligodendrocyte precursor cells did not initially produce MOLT mRNA and protein, but when they begun to differentiate into mature OLs, they started expressing MOLT. Consequently, MOLT may function as OLs become mature and may serve as a cell-surface marker for OL differentiation.
Nomoto
Hiroyuki
H
Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama 700-8558.
Yonezawa
Tomoko
T
Itoh
Kouichi
K
Ono
Katsuhiko
K
Yamamoto
Kiyotaka
K
Oohashi
Toshitaka
T
Shiraga
Fumio
F
Ohtsuki
Hiroshi
H
Ninomiya
Yoshifumi
Y
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000098:blood supply / Q000378:metabolism; D019556:COS Cells; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D004730:Endothelium, Vascular / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics*; D009836:Oligodendroglia / Q000166:cytology / Q000378:metabolism*; D021382:Protein Sorting Signals / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D021382:Protein Sorting Signals; D012333:RNA, Messenger