| First Author | Chen YC | Year | 2015 |
| Journal | PLoS One | Volume | 10 |
| Issue | 3 | Pages | e0120721 |
| PubMed ID | 25781985 | Mgi Jnum | J:229631 |
| Mgi Id | MGI:5752704 | Doi | 10.1371/journal.pone.0120721 |
| Citation | Chen YC, et al. (2015) High expression level of Tra2-beta1 is responsible for increased SMN2 exon 7 inclusion in the testis of SMA mice. PLoS One 10(3):e0120721 |
| abstractText | Spinal muscular atrophy (SMA) is an inherited neuromuscular disease caused by deletion or mutation of SMN1 gene. All SMA patients carry a nearly identical SMN2 gene, which produces low level of SMN protein due to mRNA exon 7 exclusion. Previously, we found that the testis of SMA mice (smn-/- SMN2) expresses high level of SMN2 full-length mRNA, indicating a testis-specific mechanism for SMN2 exon 7 inclusion. To elucidate the underlying mechanism, we established primary cultures of testis cells from SMA mice and analyzed them for SMN2 exon 7 splicing. We found that primary testis cells after a 2-hour culture still expressed high level of SMN2 full-length mRNA, but the level decreased after longer cultures. We then compared the protein levels of relevant splicing factors, and found that the level of Tra2-beta1 also decreased during testis cell culture, correlated with SMN2 full-length mRNA downregulation. In addition, the testis of SMA mice expressed the highest level of Tra2-beta1 among the many tissues examined. Furthermore, overexpression of Tra2-beta1, but not ASF/SF2, increased SMN2 minigene exon 7 inclusion in primary testis cells and spinal cord neurons, whereas knockdown of Tra2-beta1 decreased SMN2 exon 7 inclusion in primary testis cells of SMA mice. Therefore, our results indicate that high expression level of Tra2-beta1 is responsible for increased SMN2 exon 7 inclusion in the testis of SMA mice. This study also suggests that the expression level of Tra2-beta1 may be a modifying factor of SMA disease and a potential target for SMA treatment. |
