title: Novel nucleolar protein, midnolin, is expressed in the mesencephalon during mouse development.
abstract: Using the gene trap method and the selection of embryonic stem cells in vitro, we have identified several novel genes involved in mouse development. The detailed analysis of one of these, named midnolin (midbrain nucleolar protein), is reported here. Expression of the midnolin gene is developmentally regulated: it is strongly expressed at the mesencephalon (midbrain) of the embryo in day 12.5 (E12.5) mice. The midnolin encodes a protein of 508 amino acids (aa), which contains a Ubiquitin-like domain. The intracellular distribution of the midnolin was studied by using midnolin-green fluorescent protein (GFP) fusion proteins. Midnolin was found to be localized in the nucleus and nucleolus, but not in the cytoplasm. The nucleolar localization signal was determined to be a 28aa peptide (440-QQKRLRRKARRDARGPYHWTPSRKAGRS-467) located at the C-terminal region of the midnolin. Our results suggest that midnolin is involved in regulation of genes related to neurogenesis in the nucleolus.
authors.affiliation: Bio Signal Pathway Project, Kanagawa Academy of Science and Technology in Meiji Institute of Health Science, 540 Naruda, Odawara-shi, 250-0862, Kanagawa, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Tsukahara
authors.forename: H
authors.initials: H
authors.lastname: Suemori
authors.forename: S
authors.initials: S
authors.lastname: Noguchi
authors.forename: Z S
authors.initials: ZS
authors.lastname: Ji
authors.forename: H
authors.initials: H
authors.lastname: Tsunoo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D016466:CHO Cells; D002460:Cell Line; D003001:Cloning, Molecular; D006224:Cricetinae; D004247:DNA / Q000737:chemistry / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004622:Embryo, Mammalian / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins; D017403:In Situ Hybridization; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D008636:Mesencephalon / Q000196:embryology / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution
chemical_list: D018076:DNA, Complementary; D008164:Luminescent Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C414730:midnolin; D049452:Green Fluorescent Proteins; D004247:DNA