Characterization of a gene encoding survival motor neuron (SMN)-related protein, a constituent of the spliceosome complex.
Mutations in the gene encoding the Survival Motor Neuron (SMN) protein are responsible for autosomal recessive proximal spinal muscular atrophy (SMA). SMN orthologues have been identified in the nematode worm Caenorhabditis elegans and the yeast Schizosaccharomyces pombe but, to date, no human paralogues have been described. Here we describe identification and characterization of an SMN-related protein (SMNrp) gene that encodes a novel protein of 239 amino acids, which has recently been identified as a constituent of the spliceosome complex and designated SPF30. Significant similarity to the SMN protein is apparent only within a central region of SMNrp that represents a tudor domain. The SMNrp/SPF30 gene has been mapped to chromosome 10q23. It is differentially expressed, with abundant levels in skeletal muscle. An exclusively nuclear localization for SMNrp in cultured cells and muscle sections was revealed using GFP fusion constructs and thereafter confirmed with a polyclonal antibody raised against SMNrp. Overexpression of SMNrp as a fusion protein in HeLa cells in culture induced dose-dependent apoptosis with positive TUNEL staining. In addition to a possible role for this protein as a pro-apoptotic factor, SMN and its related protein share significant similarities in sequence and cellular function.
Talbot
K
K
Department of Human Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
Miguel-Aliaga
I
I
Mohaghegh
P
P
Ponting
C P
CP
Davies
K E
KE
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002467:Cell Nucleus / Q000737:chemistry / Q000235:genetics; D002470:Cell Survival / Q000235:genetics; D002874:Chromosome Mapping; D002879:Chromosomes, Human, Pair 10 / Q000235:genetics; D017362:Cyclic AMP Response Element-Binding Protein; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D016208:Databases, Factual; D020224:Expressed Sequence Tags; D015870:Gene Expression; D005796:Genes / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000737:chemistry; D009206:Myocardium / Q000737:chemistry; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D010179:Pancreas / Q000737:chemistry; D000072260:RNA Splicing Factors; D016601:RNA-Binding Proteins; D055532:SMN Complex Proteins; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D017381:Spliceosomes / Q000235:genetics*; D014018:Tissue Distribution
D017362:Cyclic AMP Response Element-Binding Protein; D018076:DNA, Complementary; D009419:Nerve Tissue Proteins; D000072260:RNA Splicing Factors; D016601:RNA-Binding Proteins; D055532:SMN Complex Proteins; C526478:SMNDC1 protein, human