| 背景 | Survival motor neuron protein (SMN1) is a ~31 kDa protein. The SMN complex catalyzes the assembly of small nuclear ribonucleoproteins (snRNPs), the building blocks of the spliceosome, and thereby plays an important role in the splicing of cellular pre-mRNAs. Most spliceosomal snRNPs contain a common set of Sm proteins SNRPB, SNRPD1, SNRPD2, SNRPD3, SNRPE, SNRPF and SNRPG that assemble in a heptameric protein ring on the Sm site of the small nuclear RNA to form the core snRNP (Sm core). In the cytosol, the Sm proteins SNRPD1, SNRPD2, SNRPE, SNRPF and SNRPG are trapped in an inactive 6S pICln-Sm complex by the chaperone CLNS1A that controls the assembly of the core snRNP. To assemble core snRNPs, the SMN complex accepts the trapped 5Sm proteins from CLNS1A forming an intermediate. Within the SMN complex, SMN1 acts as a structural backbone and together with GEMIN2 it gathers the Sm complex subunits. 3. Otter, S. et al. (2007) The Journal of biological chemistry 282, 5825-33. PMID: 171787135. Tripsianes, K. et al. (2011) Nature structural & molecular biology 18, 1414-20. PMID: 221019376. Yi, H. et al. (2020) Nucleic acids research 48, 895-911. PMID: 31799625 |
|---|
