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.
Hua
Yimin
Y
Department of Medicine and Program in Neuroscience, University of Massachusetts Medical School, 364 Plantation Street, LRB 325, Worcester, MA 01605, USA.
Zhou
Jianhua
J
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