Three small RNAs within the 10 kb trypanosome rRNA transcription unit are analogous to Domain VII of other eukaryotic 28S rRNAs

White, Theodore C.; Rudenko, Gloria; Borst, Piet

doi:10.1093/nar/14.23.9471

Cited by 234 publications

(137 citation statements)

References 65 publications

Supporting

Mentioning

129

Contrasting

Unclassified

Order By: Relevance

“…We could not detect obvious similarities between the PARP promoter region and the putative promoter of the ribosomal RNA transcription unit that is transcribed by RNA polymerase I (51). Similarly, obvious homologies with the region upstream of the a-amanitin sensitively transcribed miniexon genes could not be detected (10).…”

Section: Discussionmentioning

confidence: 68%

Procyclic acidic repetitive protein (PARP) genes located in an unusually small alpha-amanitin-resistant transcription unit: PARP promoter activity assayed by transient DNA transfection of Trypanosoma brucei.

Rudenko¹,

Blancq²,

Smith³

et al. 1990

Mol. Cell. Biol.

115

108

View full text Add to dashboard Cite

show abstract

Section: Discussionmentioning

confidence: 68%

Procyclic acidic repetitive protein (PARP) genes located in an unusually small alpha-amanitin-resistant transcription unit: PARP promoter activity assayed by transient DNA transfection of Trypanosoma brucei.

Rudenko¹,

Blancq²,

Smith³

et al. 1990

Mol. Cell. Biol.

115

108

View full text Add to dashboard Cite

show abstract

“…A region of complementarity (9 to 14 bp) upstream of box D in the 92/94-nt RNA (Fig. 6B) indicated an interaction within domain VI of the LSU rRNA that corresponded to small rRNA 2 in kinetoplastids (10,59). The sequences of the SSU rRNAs from L. tarentolae, T. brucei, and T. cruzi and those of the LSU rRNAs from T. brucei and T. cruzi were available; thus, a complete analysis could not be made for L. tarentolae.…”

Section: Resultsmentioning

confidence: 99%

Three Small Nucleolar RNAs Identified from the Spliced Leader-Associated RNA Locus in Kinetoplastid Protozoans

Roberts

Sturm

Yee

et al. 1998

Molecular and Cellular Biology

View full text Add to dashboard Cite

First characterized in Trypanosoma brucei, the spliced leader-associated (SLA) RNA gene locus has now been isolated from the kinetoplastids Leishmania tarentolae and Trypanosoma cruzi. In addition to the T. brucei SLA RNA, both L. tarentolae and T. cruzi SLA RNA repeat units also yield RNAs of 75 or 76 nucleotides (nt), 92 or 94 nt, and ϳ450 or ϳ350 nt, respectively, each with significant sequence identity to transcripts previously described from the T. brucei SLA RNA locus. Cell fractionation studies localize the three additional RNAs to the nucleolus; the presence of box C/D-like elements in two of the transcripts suggests that they are members of a class of small nucleolar RNAs (snoRNAs) that guide modification and cleavage of rRNAs. Candidate rRNA-snoRNA interactions can be found for one domain in each of the C/D element-containing RNAs. The putative target site for the 75/76-nt RNA is a highly conserved portion of the small subunit rRNA that contains 2-O-ribose methylation at a conserved position (Gm1830) in L. tarentolae and in vertebrates. The 92/94-nt RNA has the potential to form base pairs near a conserved methylation site in the large subunit rRNA, which corresponds to position Gm4141 of small rRNA 2 in T. brucei. These data suggest that trypanosomatids do not obey the general 5-bp rule for snoRNA-mediated methylation.Posttranscriptional modifications to the rRNAs, including endonucleolytic cleavage, 2Ј-O-ribose methylation and pseudouridinylation, are mediated by small, nucleolar RNAs (sno RNAs). The most abundant snoRNA, U3, has been identified in numerous eukaryotes, including the kinetoplastids (27) and Euglena sp. (23). A requirement for U3 snoRNA in endonucleolytic cleavages of precursor rRNA transcripts has been established in yeast and vertebrate systems (31,36). Multiple other snoRNAs have been identified that are involved in the 2Ј-O-ribose methylation and pseudouridinylation of the 18S and 25/28S rRNAs (3,22,42,43), although the precise function of many snoRNAs remains unclear.Several criteria have been used to identify snoRNAs (24,36,50), including the presence of conserved sequence motifs, association with nucleolar proteins (fibrillarin, Gar1p, and Pop1p), complementarity to pre-rRNAs, and localization to the nucleolus. Like other cellular RNAs, snoRNAs are believed to exist as ribonucleoprotein complexes (36, 50) and have been divided into two major classes based on conserved sequence elements and protein associations. The box C/D snoRNAs usually contain box C and box D elements near their 5Ј and 3Ј ends, respectively; these elements are required for snoRNP interaction with the abundant nucleolar protein, fibrillarin. In vertebrates, box C/D snoRNAs are frequently processed from the introns of protein-encoding mRNAs (54), while in plants and yeasts they may be transcribed polycistronically (32, 50). The other class, the box H/ACA snoRNAs, contains two conserved sequence motifs: box H resides in a hinge region between two stem-loop structures, and the "ACA" trinucleotide motif resides 3 ...

show abstract

“…Moreover, their large subunit contains eight pieces of rRNA, six of which result from unique cleavages of a precursor rRNA. Upon assembly, these rRNAs fulfill the functions of the 28S rRNA found in other eukaryotes (7,8). This unique multiple fragmentation strongly suggests that trypanosomatid ribosomes have pronounced differences that could be exploited for drug design.…”

mentioning

confidence: 85%

Structure and assembly model for the Trypanosoma cruzi 60S ribosomal subunit

Liu

Gutierrez-Vargas

Jia

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Ribosomes of trypanosomatids, a family of protozoan parasites causing debilitating human diseases, possess multiply fragmented rRNAs that together are analogous to 28S rRNA, unusually large rRNA expansion segments, and r-protein variations compared with other eukaryotic ribosomes. To investigate the architecture of the trypanosomatid ribosomes, we determined the 2.5-Å structure of the Trypanosoma cruzi ribosome large subunit by single-particle cryo-EM. Examination of this structure and comparative analysis of the yeast ribosomal assembly pathway allowed us to develop a stepwise assembly model for the eight pieces of the large subunit rRNAs and a number of ancillary "glue" proteins. This model can be applied to the characterization of Trypanosoma brucei and Leishmania spp. ribosomes as well. Together with other details, our atomic-level structure may provide a foundation for structurebased design of antitrypanosome drugs.ribosome structure | Trypanosoma cruzi | biogenesis | multiply fragmented rRNA | antitrypanosome drug design

show abstract

Three small RNAs within the 10 kb trypanosome rRNA transcription unit are analogous to Domain VII of other eukaryotic 28S rRNAs

Cited by 234 publications

References 65 publications

Procyclic acidic repetitive protein (PARP) genes located in an unusually small alpha-amanitin-resistant transcription unit: PARP promoter activity assayed by transient DNA transfection of Trypanosoma brucei.

Procyclic acidic repetitive protein (PARP) genes located in an unusually small alpha-amanitin-resistant transcription unit: PARP promoter activity assayed by transient DNA transfection of Trypanosoma brucei.

Three Small Nucleolar RNAs Identified from the Spliced Leader-Associated RNA Locus in Kinetoplastid Protozoans

Structure and assembly model for the Trypanosoma cruzi 60S ribosomal subunit

Contact Info

Product

Resources

About