Journal article

Publication year: 2009

Pages: 1650-1664

Journal: Genes & Development

Volume number: 23

Issue number: 14

ISSN: 0890-9369

eISSN: 1549-5477

Open access status: Gold

DOI Link: https://doi.org/10.1101/gad.526109

Publisher: Cold Spring Harbor Laboratory Press

Abstract: 
Spliceosomal small nuclear ribonucleoproteins (snRNPs) in trypanosomes contain either the canonical heptameric Sm ring (U1, U5, spliced leader snRNPs), or variant Sm cores with snRNA-specific Sm subunits (U2, U4 snRNPs). Searching for specificity factors, we identified SMN and Gemin2 proteins that are highly divergent from known orthologs. SMN is splicing-essential in trypanosomes and nuclear-localized, suggesting that Sm core assembly in trypanosomes is nuclear. We demonstrate in vitro that SMN is sufficient to confer specificity of canonical Sm core assembly and to discriminate against binding to nonspecific RNA and to U2 and U4 snRNAs. SMN interacts transiently with the SmD3B subcomplex, contacting specifically SmB. SMN remains associated throughout the assembly of the Sm heteroheptamer and dissociates only when a functional Sm site is incorporated. These data establish a novel role of SMN, mediating snRNP specificity in Sm core assembly, and yield new biochemical insight into the mechanism of SMN activity.

Harvard Citation style: Palfi, Z., Jae, N., Preußer, C., Kaminska, K., Bujnicki, J., Lee, J., et al. (2009) SMN-assisted assembly of snRNP-specific Sm cores in trypanosomes, Genes & Development, 23(14), pp. 1650-1664. https://doi.org/10.1101/gad.526109

APA Citation style: Palfi, Z., Jae, N., Preußer, C., Kaminska, K., Bujnicki, J., Lee, J., Günzl, A., Kambach, C., Urlaub, H., & Bindereif, A. (2009). SMN-assisted assembly of snRNP-specific Sm cores in trypanosomes. Genes & Development. 23(14), 1650-1664. https://doi.org/10.1101/gad.526109