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Evolutionary conservation of minor U12-type spliceosome between plants and humans.
RNA. 2005 Jul; 11(7):1095-107.RNA

Abstract

Splicing of rare, U12-type or AT-AC introns is mediated by a distinct spliceosome that assembles from U11, U12, U4atac, U6atac, and U5 snRNPs. Although in human cells the protein composition of minor and major snRNPs is similar, differences, particularly in U11 and U12 snRNPs, have been recently described. We have identified an Arabidopsis U11 snRNP-specific 35K protein as an interacting partner of an RS-domain-containing cyclophilin. By using a transient expression system in Arabidopsis protoplasts, we show that the 35K protein incorporates into snRNP. Oligo affinity selection and glycerol gradient centrifugation revealed that the Arabidopsis 35K protein is present in monomeric U11 snRNP and in U11/U12-di snRNP. The interaction of the 35K protein with Arabidopsis SR proteins together with its strong sequence similarity to U1-70K suggests that its function in splicing of minor introns is analogous to that of U1-70K. Analysis of Arabidopsis and Oryza sativa genome sequences revealed that all U11/U12-di-snRNP-specific proteins are conserved in dicot and monocot plants. In addition, we have identified an Arabidopsis gene encoding the homolog of U4atac snRNA and a second Arabidopsis gene encoding U6atac snRNA. Secondary structure predictions indicate that the Arabidopsis U4atac is able to form dimeric complexes with both Arabidopsis U6atac snRNAs. As revealed by RNaseA/T1 protection assay, the U4atac snRNA gene is expressed as an ~160-nt RNA, whereas the second U6atac snRNA gene seems to be a pseudogene. Taken together, our data indicate that recognition and splicing of minor, AT-AC introns in plants is highly similar to that in humans.

Authors+Show Affiliations

Max F. Perutz Laboratories, University Departments at the Vienna Biocenter, Department of Biochemistry, Medical University of Vienna, A-1030 Vienna, Austria. zdravko.lorkovic@univie.ac.atNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15987817

Citation

Lorkovic, Zdravko J., et al. "Evolutionary Conservation of Minor U12-type Spliceosome Between Plants and Humans." RNA (New York, N.Y.), vol. 11, no. 7, 2005, pp. 1095-107.
Lorkovic ZJ, Lehner R, Forstner C, et al. Evolutionary conservation of minor U12-type spliceosome between plants and humans. RNA. 2005;11(7):1095-107.
Lorkovic, Z. J., Lehner, R., Forstner, C., & Barta, A. (2005). Evolutionary conservation of minor U12-type spliceosome between plants and humans. RNA (New York, N.Y.), 11(7), 1095-107.
Lorkovic ZJ, et al. Evolutionary Conservation of Minor U12-type Spliceosome Between Plants and Humans. RNA. 2005;11(7):1095-107. PubMed PMID: 15987817.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Evolutionary conservation of minor U12-type spliceosome between plants and humans. AU - Lorkovic,Zdravko J, AU - Lehner,Reinhard, AU - Forstner,Christina, AU - Barta,Andrea, PY - 2005/7/1/pubmed PY - 2005/8/9/medline PY - 2005/7/1/entrez SP - 1095 EP - 107 JF - RNA (New York, N.Y.) JO - RNA VL - 11 IS - 7 N2 - Splicing of rare, U12-type or AT-AC introns is mediated by a distinct spliceosome that assembles from U11, U12, U4atac, U6atac, and U5 snRNPs. Although in human cells the protein composition of minor and major snRNPs is similar, differences, particularly in U11 and U12 snRNPs, have been recently described. We have identified an Arabidopsis U11 snRNP-specific 35K protein as an interacting partner of an RS-domain-containing cyclophilin. By using a transient expression system in Arabidopsis protoplasts, we show that the 35K protein incorporates into snRNP. Oligo affinity selection and glycerol gradient centrifugation revealed that the Arabidopsis 35K protein is present in monomeric U11 snRNP and in U11/U12-di snRNP. The interaction of the 35K protein with Arabidopsis SR proteins together with its strong sequence similarity to U1-70K suggests that its function in splicing of minor introns is analogous to that of U1-70K. Analysis of Arabidopsis and Oryza sativa genome sequences revealed that all U11/U12-di-snRNP-specific proteins are conserved in dicot and monocot plants. In addition, we have identified an Arabidopsis gene encoding the homolog of U4atac snRNA and a second Arabidopsis gene encoding U6atac snRNA. Secondary structure predictions indicate that the Arabidopsis U4atac is able to form dimeric complexes with both Arabidopsis U6atac snRNAs. As revealed by RNaseA/T1 protection assay, the U4atac snRNA gene is expressed as an ~160-nt RNA, whereas the second U6atac snRNA gene seems to be a pseudogene. Taken together, our data indicate that recognition and splicing of minor, AT-AC introns in plants is highly similar to that in humans. SN - 1355-8382 UR - https://www.unboundmedicine.com/medline/citation/15987817/Evolutionary_conservation_of_minor_U12_type_spliceosome_between_plants_and_humans_ L2 - http://www.rnajournal.org/cgi/pmidlookup?view=long&pmid=15987817 DB - PRIME DP - Unbound Medicine ER -