Survival motor neuron protein facilitates assembly of stress granules.
The survival motor neuron (SMN) protein forms cytoplasmic granules when overexpressed. We report here that SMN co-localizes with TIA-1/R and G3BP, protein assemblers of stress granules (SGs), and that SMN is co-immunoprecipitated with TIA-1/R, suggesting that SMN granules are SGs. Formation of SMN granules precedes accumulation of TIA-1/R, indicating that SMN serves as a facilitator of SG formation. However, the exon 7 skipping product, SMNDelta7, is largely retained in the nucleus and forms nuclear granules, indicating that exon 7 is critical for SG formation. Our findings reveal a novel SMN function and possible SG involvement in the pathogenesis of spinal muscular atrophy.
Department of Medicine and Program in Neuroscience, University of Massachusetts Medical School, 364 Plantation Street, LRB 325, Worcester, MA 01605, USA.
Yimin
Y
Hua
Jianhua
J
Zhou
D000595:Amino Acid Sequence; D001665:Binding Sites; D045744:Cell Line, Tumor; D003594:Cytoplasmic Granules / Q000235:genetics / Q000502:physiology*; D005347:Fibroblasts; D006367:HeLa Cells; D006358:Hot Temperature; D006801:Humans; D008969:Molecular Sequence Data; D009046:Motor Neurons / Q000502:physiology*; D016296:Mutagenesis; D009419:Nerve Tissue Proteins / Q000502:physiology*; D009447:Neuroblastoma; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D017384:Sequence Deletion; D013314:Stress, Mechanical
D009419:Nerve Tissue Proteins; D016601:RNA-Binding Proteins; C076751:TIAL1 protein, human