title: Nucleolar targeting of coilin is regulated by its hypomethylation state.
abstract: Coilin, a molecular marker for Cajal bodies (CBs), is a phosphoprotein that contains a cryptic nucleolar localization signal and multiple interacting domains, such as the RG-box. Post-translational symmetrical dimethylation of arginines on the coilin RG-box is required for the recruitment of the survival motor neuron (SMN) protein and splicing small ribonucleoproteins (snRNPs) to CBs. Here, we analyze the role of the methylation state of coilin in the regulation of its localization to the nucleolus. We use the MCF7 MTAP(-/-) cell line, which lacks the gene encoding 5'-methylthioadenosine phosphorylase (MTAP). This is a key enzyme of the methionine salvage pathway. The reduction of the levels of coilin methylation causes disruption of the canonical CBs and coilin redistribution to nucleoplasmic microfoci and to the nucleolus. Intranucleolar coilin is unmethylated and appears restricted to the dense fibrillar component. Interestingly, intranucleolar coilin is not associated with SMN or snRNPs, and does not interfere with global transcriptional activity. Overexpression of wild-type MTAP reverts the intranucleolar localization of coilin and the disruption of CBs to the normal coilin phenotype. Our results suggest the existence of a dynamic flux of coilin between CBs, nucleoplasm and nucleolus, and indicate that coilin methylation plays a key role in this process.
authors.affiliation: Department of Anatomy and Cell Biology, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) and IFIMAV, University of Cantabria, Santander, Spain.
authors.forename: Olga
authors.initials: O
authors.lastname: Tapia
authors.forename: Rocio
authors.initials: R
authors.lastname: Bengoechea
authors.forename: Maria T
authors.initials: MT
authors.lastname: Berciano
authors.forename: Miguel
authors.initials: M
authors.lastname: Lafarga
mesh_terms: D000818:Animals; D002460:Cell Line; D045744:Cell Line, Tumor; D002466:Cell Nucleolus / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D020541:Coiled Bodies / Q000235:genetics / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D005786:Gene Expression Regulation; D006801:Humans; D008745:Methylation; D051379:Mice; D009687:Nuclear Proteins / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D011683:Purine-Nucleoside Phosphorylase / Q000235:genetics / Q000378:metabolism; D012326:RNA Splicing; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017411:Ribonucleoproteins, Small Nuclear / Q000378:metabolism; D055532:SMN Complex Proteins / Q000378:metabolism
chemical_list: D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D017411:Ribonucleoproteins, Small Nuclear; D055532:SMN Complex Proteins; C068921:p80-coilin; D011683:Purine-Nucleoside Phosphorylase; C021784:5'-methylthioadenosine phosphorylase
references.citation: Mol Biol Cell. 2009 Dec;20(24):5250-9
references.pmid: 19846657
references.citation: Dev Cell. 2002 Sep;3(3):329-37
references.pmid: 12361597
references.citation: Cell Mol Life Sci. 2008 Apr;65(7-8):1256-71
references.pmid: 18322647
references.citation: Chromosoma. 2006 Oct;115(5):343-54
references.pmid: 16575476
references.citation: Chromosoma. 2004 Jun;112(8):398-409
references.pmid: 15164213
references.citation: Nucleic Acids Res. 1994 Oct 25;22(21):4462-9
references.pmid: 7971277
references.citation: Genes Cells. 2007 Jan;12(1):105-17
references.pmid: 17212658
references.citation: J Biol Chem. 2007 Jul 20;282(29):21477-86
references.pmid: 17548352
references.citation: Exp Cell Res. 1991 Jul;195(1):27-37
references.pmid: 2055273
references.citation: Cancer Res. 2000 Oct 1;60(19):5543-7
references.pmid: 11034100
references.citation: Proc Natl Acad Sci U S A. 1981 May;78(5):2737-41
references.pmid: 6789322
references.citation: Cancer Res. 1996 Dec 15;56(24):5653-8
references.pmid: 8971171
references.citation: J Struct Biol. 1990 Jul-Sep;104(1-3):120-7
references.pmid: 2088441
references.citation: Chromosoma. 2009 Aug;118(4):437-43
references.pmid: 19404660
references.citation: J Cell Biol. 2007 Aug 27;178(5):733-40
references.pmid: 17709427
references.citation: J Exp Med. 1991 Jun 1;173(6):1407-19
references.pmid: 2033369
references.citation: J Cell Biol. 1993 Feb;120(4):841-52
references.pmid: 7679389
references.citation: EMBO J. 2001 Feb 1;20(3):541-51
references.pmid: 11157760
references.citation: J Cell Biol. 1998 Jul 27;142(2):319-29
references.pmid: 9679133
references.citation: Annu Rev Cell Dev Biol. 2005;21:105-31
references.pmid: 16212489
references.citation: J Comp Neurol. 1991 Jun 15;308(3):329-39
references.pmid: 1865004
references.citation: Glia. 2002 Dec;40(3):378-88
references.pmid: 12420317
references.citation: Exp Cell Res. 1997 Jan 10;230(1):84-93
references.pmid: 9013710
references.citation: Dev Cell. 2009 Nov;17(5):639-47
references.pmid: 19922869
references.citation: Cell. 1992 Jul 10;70(1):127-38
references.pmid: 1623516
references.citation: J Cell Biol. 2001 Jul 23;154(2):293-307
references.pmid: 11470819
references.citation: J Cell Biol. 2000 Dec 25;151(7):1561-74
references.pmid: 11134083
references.citation: Exp Cell Res. 1998 Sep 15;243(2):290-304
references.pmid: 9743589
references.citation: Histochem Cell Biol. 2008 Jan;129(1):5-11
references.pmid: 17994245
references.citation: RNA. 2001 Nov;7(11):1531-42
references.pmid: 11720283
references.citation: Mol Cell. 2009 Jan 16;33(1):1-13
references.pmid: 19150423
references.citation: J Cell Biol. 1999 Nov 15;147(4):715-28
references.pmid: 10562276
references.citation: J Cell Sci. 1994 Feb;107 ( Pt 2):385-99
references.pmid: 8207070
references.citation: Exp Cell Res. 1996 Oct 10;228(1):125-31
references.pmid: 8892979
references.citation: Curr Opin Cell Biol. 2006 Jun;18(3):317-24
references.pmid: 16632338
references.citation: Cancer Genet Cytogenet. 2001 Mar;125(2):131-8
references.pmid: 11369056
references.citation: PLoS One. 2009 May 29;4(5):e5735
references.pmid: 19478948
references.citation: J Biol Chem. 2001 Aug 31;276(35):32971-6
references.pmid: 11413150
references.citation: Genes Dev. 2001 Oct 15;15(20):2720-9
references.pmid: 11641277
references.citation: J Neurocytol. 1998 Apr;27(4):205-17
references.pmid: 10640180
references.citation: Mol Cancer Ther. 2005 Dec;4(12):1860-6
references.pmid: 16373701
references.citation: Anat Rec. 1969 Aug;164(4):403-31
references.pmid: 5797926
references.citation: Proc Natl Acad Sci U S A. 1996 Jun 11;93(12):6203-8
references.pmid: 8650244
references.citation: Traffic. 2009 Nov;10(11):1585-98
references.pmid: 19735367
references.citation: Mol Biol Cell. 2006 Dec;17(12):4972-81
references.pmid: 16987958
references.citation: J Struct Biol. 2007 Jun;158(3):410-20
references.pmid: 17275332
references.citation: J Cell Biol. 1995 Nov;131(4):817-31
references.pmid: 7490287
references.citation: Int J Biochem Cell Biol. 2004 Nov;36(11):2125-30
references.pmid: 15313459
references.citation: Mol Endocrinol. 2009 Apr;23(4):425-33
references.pmid: 19164444
references.citation: Annu Rev Cell Dev Biol. 2000;16:273-300
references.pmid: 11031238
references.citation: Biochem Pharmacol. 1982 Feb 1;31(3):277-88
references.pmid: 6803807
references.citation: J Comp Neurol. 2001 Feb 5;430(2):250-63
references.pmid: 11135260
references.citation: Eur J Neurosci. 1996 May;8(5):892-905
references.pmid: 8743737
references.citation: J Cell Sci. 2003 Jan 15;116(Pt 2):303-12
references.pmid: 12482916
references.citation: Mol Biol Cell. 2009 Mar;20(6):1661-70
references.pmid: 19158395
references.citation: Mol Biol Cell. 2000 Dec;11(12):4159-71
references.pmid: 11102515
references.citation: Int Rev Cytol. 2006;255:177-235
references.pmid: 17178467
references.citation: J Cell Biol. 2002 Dec 23;159(6):957-69
references.pmid: 12486110