title: Bipartite nuclear localization signal of matrin 3 is essential for vertebrate cells.
abstract: Matrin 3, a nuclear matrix protein has potential (1) to withhold promiscuously edited RNAs within the nucleus in cooperation with p54(nrb) and PSF, (2) to mediate NMDA-induced neuronal death, and (3) to modulate promoter activity of genes proximal to matrix/scaffold attachment region (MAR/SAR). We identified a bipartite nuclear localization signal (NLS) of chicken matrin 3 (cmatr3) at residues 583-602. By expressing green fluorescent protein (GFP) fused to the NLS mutant in chicken DT40 cells, we showed an essential role of the NLS for cell proliferation. Furthermore, we showed that both clusters of basic amino acids and a linker of the bipartite NLS were essential and sufficient for the nuclear import of GFP. Exogenous cmatr3 rescued the HeLa cells where human matrin 3 was suppressed by RNA interference, but cmatr3 containing deletions at either of the basic amino acid clusters or the linker could not.
authors.affiliation: Department of Bioengineering Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Hisada-Ishii
authors.forename: Mizuki
authors.initials: M
authors.lastname: Ebihara
authors.forename: Nao
authors.initials: N
authors.lastname: Kobayashi
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kitagawa
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000502:physiology*; D000595:Amino Acid Sequence; D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D002645:Chickens; D020868:Gene Silencing; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D008223:Lymphoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008969:Molecular Sequence Data; D019913:Nuclear Localization Signals / Q000378:metabolism*; D034521:Nuclear Matrix-Associated Proteins / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: C518587:MATR3 protein, human; D019913:Nuclear Localization Signals; D034521:Nuclear Matrix-Associated Proteins; D016601:RNA-Binding Proteins