Mouse-Musashi-1, a neural RNA-binding protein highly enriched in the mammalian CNS stem cell.
There is increasing interest in the role of RNA-binding proteins during neural development. Drosophila Musashi is one of the neural RNA-binding proteins essential for neural development and required for asymmetric cell divisions in the Drosophila adult sensory organ development. Here, a novel mammalian neural RNA-binding protein, mouse-Musashi-1, was identified based on the homology to Drosophila Musashi and Xenopus NRP-1. In the developing CNS, mouse-Musashi-1 protein was highly enriched in the CNS stem cell. Single-cell culture experiments indicated that mouse-Musashi-1 expression is associated with neural precursor cells that are capable of generating neurons and glia. In contrast, in fully differentiated neuronal and glial cells mouse-Musashi-1 expression is lost. This expression pattern of mouse-Musashi-1 is complementary to that of another mammalian neural RNA-binding protein, Hu (a mammalian homologue of a Drosophila neuronal RNA-binding protein Elav), that is expressed in postmitotic neurons within the CNS. In vitro studies indicated that mouse-Musashi-1 possesses binding preferences on poly(G) RNA homopolymer, whereas Hu is known to preferentially bind to short A/U-rich regions in RNA. Based on their differential expression patterns and distinct preferential target RNA sequences, we believe that the mouse-Musashi-1 and Hu proteins may play distinct roles in neurogenesis, either through sequential regulatory mechanisms or differential sorting of mRNA populations during asymmetric division of neural precursor cells.
Sakakibara
S
S
Department of Molecular Neurobiology, Institute of Basic Medical Sciences, University of Tsukuba, Ibaraki, Japan.
Imai
T
T
Hamaguchi
K
K
Okabe
M
M
Aruga
J
J
Nakajima
K
K
Yasutomi
D
D
Nagata
T
T
Kurihara
Y
Y
Uesugi
S
S
Miyata
T
T
Ogawa
M
M
Mikoshiba
K
K
Okano
H
H
D000595:Amino Acid Sequence; D000818:Animals; D002490:Central Nervous System / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004330:Drosophila; D029721:Drosophila Proteins; D018507:Gene Expression Regulation, Developmental; D007381:Intermediate Filament Proteins / Q000378:metabolism; D051379:Mice; D008813:Mice, Inbred ICR; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology; D064231:Nestin; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology; D012261:Ribonucleoproteins / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013234:Stem Cells / Q000378:metabolism*; D014981:Xenopus; D029867:Xenopus Proteins
D018076:DNA, Complementary; D029721:Drosophila Proteins; D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; C577485:Nes protein, mouse; D064231:Nestin; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D029867:Xenopus Proteins; C088623:msi protein, Drosophila; C068598:Msi1 protein, Xenopus