title: Symmetrical dimethylarginine methylation is required for the localization of SMN in Cajal bodies and pre-mRNA splicing.
abstract: The nuclear structures that contain symmetrical dimethylated arginine (sDMA)-modified proteins and the role of this posttranslational modification is unknown. Here we report that the Cajal body is a major epitope in HeLa cells for an sDMA-specific antibody and that coilin is an sDMA-containing protein as analyzed by using the sDMA-specific antibody and matrix-assisted laser desorption ionization time of flight mass spectrometry. The methylation inhibitor 5'-deoxy-5'-methylthioadenosine reduces the levels of coilin methylation and causes the appearance of SMN-positive gems. In cells devoid of Cajal bodies, such as primary fibroblasts, sDMA-containing proteins concentrated in speckles. Cells from a patient with spinal muscular atrophy, containing low levels of the methyl-binding protein SMN, localized sDMA-containing proteins in the nucleoplasm as a discrete granular pattern. Splicing reactions are efficiently inhibited by using the sDMA-specific antibody or by using hypomethylated nuclear extracts, showing that active spliceosomes contain sDMA polypeptides and suggesting that arginine methylation is important for efficient pre-mRNA splicing. Our findings support a model in which arginine methylation is important for the localization of coilin and SMN in Cajal bodies.
authors.affiliation: Terry Fox Molecular Oncology Group, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montréal, Québec, Canada H3T 1E2.
authors.forename: Francois-Michel
authors.initials: FM
authors.lastname: Boisvert
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Cote
authors.forename: Marie-Chloe
authors.initials: MC
authors.lastname: Boulanger
authors.forename: Patrick
authors.initials: P
authors.lastname: Cleroux
authors.forename: Francois
authors.initials: F
authors.lastname: Bachand
authors.forename: Chantal
authors.initials: C
authors.lastname: Autexier
authors.forename: Stephane
authors.initials: S
authors.lastname: Richard
mesh_terms: D000906:Antibodies / Q000378:metabolism; D001120:Arginine / Q000031:analogs & derivatives / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D020541:Coiled Bodies / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005347:Fibroblasts / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D006367:HeLa Cells; D006801:Humans; D013058:Mass Spectrometry; D008745:Methylation; D008856:Microscopy, Fluorescence; D009134:Muscular Atrophy, Spinal / Q000378:metabolism; D011233:Precipitin Tests; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014162:Transfection
chemical_list: D000906:Antibodies; D012333:RNA, Messenger; D004247:DNA; D001120:Arginine