Purification of native survival of motor neurons complexes and identification of Gemin6 as a novel component

J Biol Chem. 2002 Mar 1;277(9):7540-5. doi: 10.1074/jbc.M110141200. Epub 2001 Dec 17.

Abstract

The survival of motor neurons (SMN) protein, the product of the gene responsible for the motor neuron degenerative disease spinal muscular atrophy (SMA), is part of a large macromolecular complex. The SMN complex is localized in both the cytoplasm and the nucleus and contains SMN, Gemin2, Gemin3, Gemin4, Gemin5, and a few not yet identified proteins. The SMN complex plays a key role in the biogenesis of spliceosomal small nuclear ribonucleoproteins (snRNPs) and other ribonucleoprotein particles. As a step toward the complete characterization of the components of the SMN complex, we generated stable cell lines that express FLAG-tagged SMN or Gemin2 under the control of a tetracycline-inducible promoter. Native SMN complexes of identical protein composition to those isolated by immunoprecipitation with anti-SMN antibodies were purified by affinity chromatography from extracts of both cell lines. Here we report the identification by mass spectrometry of a novel protein component of the SMN complex termed Gemin6. Co-immunoprecipitation, immunolocalization, and in vitro binding experiments demonstrate that Gemin6 is a component of the SMN complex that localizes to gems and interacts with several Sm proteins of the spliceosomal snRNPs.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Blotting, Western
  • Cell Line
  • Cell Survival
  • DNA / metabolism
  • HeLa Cells
  • Humans
  • Mass Spectrometry
  • Microscopy, Fluorescence
  • Molecular Sequence Data
  • Motor Neurons / cytology*
  • Nerve Tissue Proteins / biosynthesis*
  • Nerve Tissue Proteins / chemistry
  • Nerve Tissue Proteins / genetics
  • Nuclear Proteins*
  • Precipitin Tests
  • Promoter Regions, Genetic
  • Protein Binding
  • Recombinant Fusion Proteins / metabolism
  • Ribonucleoproteins, Small Nuclear
  • SMN Complex Proteins
  • Sequence Homology, Amino Acid
  • Spliceosomes / metabolism

Substances

  • GEMIN6 protein, human
  • Nerve Tissue Proteins
  • Nuclear Proteins
  • Recombinant Fusion Proteins
  • Ribonucleoproteins, Small Nuclear
  • SMN Complex Proteins
  • DNA

Associated data

  • GENBANK/AF453443