Domain structure of U2 and U4/U6 small nuclear ribonucleoprotein particles from Trypanosoma brucei: identification of trans-spliceosomal specific RNA-protein interactions.
AUTOR(ES)
Günzl, A
RESUMO
Maturation of mRNAs in trypanosomes involves trans splicing of the 5' end of the spliced leader RNA and the exons of polycistronic pre-mRNAs, requiring small nuclear ribonucleoproteins (snRNPs) as cofactors. We have mapped protein-binding sites in the U2 and U4/U6 snRNPs by a combination of RNase H protection analysis, native gel electrophoresis, and CsCl density gradient centrifugation. In the U2 snRNP, protein binding occurs primarily in the 3'-terminal domain; through U2 snRNP reconstitution and chemical modification-interference assays, we have identified discrete positions within stem-loop IV of Trypanosoma brucei U2 RNA that are essential for protein binding; significantly, some of these positions differ from the consensus sequence derived from cis-spliceosomal U2 RNAs. In the U4/U6 snRNP, the major protein-binding region is contained within the 3'-terminal half of U4 RNA. In sum, while the overall domain structure of the U2 and U4/U6 snRNPs is conserved between cis- and trans-splicing systems, our data suggest that there are also trans-spliceosomal specific determinants of RNA-protein binding.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=364191Documentos Relacionados
- The trans-spliceosomal U2 snRNP protein 40K of Trypanosoma brucei: cloning and analysis of functional domains reveals homology to a mammalian snRNP protein.
- Tetrahymena telomerase ribonucleoprotein RNA-protein interactions.
- Isolation and sequence of four small nuclear U RNA genes of Trypanosoma brucei subsp. brucei: identification of the U2, U4, and U6 RNA analogs.
- Autoantibodies to ribonucleoprotein particles containing U2 small nuclear RNA.
- PRP4: a protein of the yeast U4/U6 small nuclear ribonucleoprotein particle.