Identification of Survival Motor Neuron as a Transcriptional Activator-Binding Protein

• Published in: Human molecular genetics 1999-07, Vol.8 (7), p.1219-1226
• Main Authors: Strasswimmer, John, Lorson, Christian L., Breiding, David E., Chen, Jason J., Le, Than, Burghes, Arthur H. M., Androphy, Elliot J.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Cyclic AMP Response Element-Binding Protein; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; DNA-Binding Proteins - metabolism; Escherichia coli; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation; HeLa Cells; Humans; Medical sciences; Molecular and cellular biology; Molecular genetics; Muscular Atrophy, Spinal - genetics; Muscular Atrophy, Spinal - metabolism; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - isolation & purification; Nerve Tissue Proteins - metabolism; Neurology; Papillomavirus; Protein Binding; RNA-Binding Proteins; Saccharomyces cerevisiae; SMN Complex Proteins; Trans-Activators - metabolism; Transcription. Transcription factor. Splicing. Rna processing; Viral Proteins - metabolism
• ISSN: 0964-6906; 1460-2083; 1460-2083
• DOI: 10.1093/hmg/8.7.1219

Spinal muscular atrophy (SMA) is an inherited neuromuscular disease characterized by specific degeneration of spinal cord anterior horn cells and subsequent muscle atrophy. Survival motor neuron (SMN), located on chromosome 5q13, is the SMA-determining gene. In the nucleus, SMN is present in large foci called gems, the function of which is not yet known, while cytoplasmic SMN has been implicated in snRNP biogenesis. In SMA patients, SMN protein levels and the number of gems generally correlate with disease severity, suggesting a critical nuclear function for SMN. In a screen for proteins associated with the nuclear transcription activator ‘E2’ of papillomavirus, two independent SMN cDNAs were isolated. The E2 and SMN proteins were found to associate specifically in vitro and in vivo. Expression of SMN enhanced E2-dependent transcriptional activation, and patient-derived SMN missense mutations reduced E2 gene expression. Our results demonstrate that SMN interacts with a nuclear transcription factor and imply that SMN may serve a role in regulating gene expression. These observations suggest that SMA may in part result from abnormal gene expression and that E2 may influence viral gene expression through SMN interaction.