Spliceosomal introns in a deep-branching eukaryote

VAŇÁČOVÁ, Štěpánka, Y. WEIHONG, Jane M. CARLTON and Patricia J. JOHNSON. Spliceosomal introns in a deep-branching eukaryote. Proceedings of the National Academy of Sciences of the U.S.A. 2005, vol. 102, No 12, p. 4430-4435. ISSN 1091-6490.

Basic information

• Original name: Spliceosomal introns in a deep-branching eukaryote
• Name in Czech: Spliceosomal introns in a deep-branching eukaryote
• Authors: VAŇÁČOVÁ, Štěpánka (203 Czech Republic, guarantor), Y. WEIHONG (156 China), Jane M. CARLTON (826 United Kingdom of Great Britain and Northern Ireland) and Patricia J. JOHNSON (840 United States of America).
• Edition: Proceedings of the National Academy of Sciences of the U.S.A. 2005, 1091-6490.

Other information

• Original language: English
• Type of outcome: Article in a journal
• Field of Study: Genetics and molecular biology
• Country of publisher: United States of America
• Confidentiality degree: is not subject to a state or trade secret
• RIV identification code: RIV/00216224:14310/05:00036234
• Organization unit: Faculty of Science
• UT WoS: 000227854800039
• Keywords (in Czech): Trichomonas; pre-mRNA splicing; intron; evolution; deep branching eukaryote
• Keywords in English: Trichomonas; pre-mRNA splicing; intron; evolution; deep branching eukaryote
• Tags: deep branching eukaryote, Evolution, intron, pre-mRNA splicing, Trichomonas
• Tags: International impact, Reviewed

Abstract

Eukaryotes have evolved elaborate splicing mechanisms to remove introns that would otherwise destroy the protein-coding capacity of genes. Nuclear premRNA splicing requires sequence motifs in the intron and is mediated by a ribonucleoprotein complex, the spliceosome. Here we demonstrate the presence of a splicing apparatus in the protist Trichomonas vaginalis and show that RNA motifs found in yeast and metazoan introns are required for splicing. We also describe the first introns in this deep-branching lineage. The positions of these introns are often conserved in orthologous genes, indicating they were present in a common ancestor of trichomonads, yeast, and metazoa. All examined T. vaginalis introns have a highly conserved 12-nt 3-prime splice-site motif that encompasses the branch point and is necessary for splicing. This motif is also found in the only described intron in a gene from another deep-branching eukaryote, Giardia intestinalis. These studies demonstrate the conservation of intron splicing signals across large evolutionary distances, reveal unexpected motif conservation in deep-branching lineages that suggest a simplified mechanism of splicing in primitive unicellular eukaryotes, and support the presence of introns in the earliest eukaryote.

Abstract (in Czech)

Eukaryotes have evolved elaborate splicing mechanisms to remove introns that would otherwise destroy the protein-coding capacity of genes. Nuclear premRNA splicing requires sequence motifs in the intron and is mediated by a ribonucleoprotein complex, the spliceosome. Here we demonstrate the presence of a splicing apparatus in the protist Trichomonas vaginalis and show that RNA motifs found in yeast and metazoan introns are required for splicing. We also describe the first introns in this deep-branching lineage. The positions of these introns are often conserved in orthologous genes, indicating they were present in a common ancestor of trichomonads, yeast, and metazoa. All examined T. vaginalis introns have a highly conserved 12-nt 3-prime splice-site motif that encompasses the branch point and is necessary for splicing. This motif is also found in the only described intron in a gene from another deep-branching eukaryote, Giardia intestinalis. These studies demonstrate the conservation of intron splicing signals across large evolutionary distances, reveal unexpected motif conservation in deep-branching lineages that suggest a simplified mechanism of splicing in primitive unicellular eukaryotes, and support the presence of introns in the earliest eukaryote.