α‐ and β‐tubulin mRNAs of <i>Trypanosoma cruzi</i> originate from a single multicistronic transcript

Soares, C. M. A.; Carvalho, E.F.; Ürményi, Turán P.; Carvalho, Jose Francisco; Castro, F. T. de; Rondinelli, Edson

doi:10.1016/0014-5793(89)80784-7

Cited by 28 publications

(14 citation statements)

References 29 publications

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“…Detection of nascent RNAs sensitive and resistant to RNA polymerase inhibitors by dot blotting. Nascent transcripts from epimastigotes in the logarithmic phase of growth (non-treated) were hybridized to the following membrane-bound cloned DNAs: T. cruzi 18S rDNA (18S) (31), the T. cruzi α-tubulin gene (pTcα3) (58), the T. cruzi tRNA gene (tRNA), the sequences coding for full-length L1Tc (L1Tc) or L1Tc endonuclease (NL1Tc), L1Tc reverse transcriptase (RT), and the L1Tc nucleic acid chaperone protein (C2-L1Tc). Run-on was also performed with nuclei incubated in the presence of 1mg/ml of α-amanitin, 0.6% of sarkosyl and 8 μM of tagetitoxin.…”

Section: Resultsmentioning

confidence: 99%

The L1Tc non-LTR retrotransposon of Trypanosoma cruzi contains an internal RNA-pol II-dependent promoter that strongly activates gene transcription and generates unspliced transcripts

Heras

López

Olivares

et al. 2007

Nucleic Acids Research

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L1Tc is the best represented autonomous LINE of the Trypanosoma cruzi genome, throughout which several functional copies may exist. In this study, we show that the first 77 bp of L1Tc (Pr77) (also present in the T. cruzi non-autonomous retrotransposon NARTc, in the Trypanosoma brucei RIME/ingi elements, and in the T. cruzi, T. brucei and Leishmania major degenerate L1Tc/ingi-related elements [DIREs]) behave as a promoter element that activates gene transcription. The transcription rate promoted by Pr77 is 10–14-fold higher than that mediated by sequences located upstream from the T. cruzi tandemly repeated genes KMP11 and the GAPDH. The Pr77 promoter-derived mRNAs initiate at nucleotide +1 of L1Tc, are unspliced and translated. L1Tc transcripts show a moderate half life and are RNA pol II dependent. The presence of an internal promoter at the 5′ end of L1Tc favors the production of full-length L1Tc RNAs and reinforces the hypothesis that this mobile element may be naturally autonomous in its transposition.

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Section: Resultsmentioning

confidence: 99%

The L1Tc non-LTR retrotransposon of Trypanosoma cruzi contains an internal RNA-pol II-dependent promoter that strongly activates gene transcription and generates unspliced transcripts

Heras

López

Olivares

et al. 2007

Nucleic Acids Research

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“…The 3Ј-UTR-II probe was obtained by HindIII plus SacI double digestion of clone pTC6, which is a pBluescript derivative, including the PCR amplification product of the 3Ј-UTR-II and downstream sequences (this product was used to generate the construct pXcat70-II (see above)). The ␣-tubulin probe was obtained from clone pTc␣3 (26). The Escherichia coli CAT probe was obtained from clone pBlCAT (17).…”

Section: Methodsmentioning

confidence: 99%

The Translational Efficiencies of the Two Leishmania infantum HSP70 mRNAs, Differing in Their 3′-Untranslated Regions, Are Affected by Shifts in the Temperature of Growth through Different Mechanisms

Folgueira

Quijada

Soto

et al. 2005

Journal of Biological Chemistry

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Exposure of Leishmania promastigotes to the temperature of their mammalian hosts induces a typical heat-shock response. In Leishmania infantum, HSP70 is encoded by two types of genes that differ in their 3-untranslated regions (3-UTRs). Previously, we have shown that specific transcripts for each gene are present in promastigotes growing at normal temperature (26°C), but only transcripts with 3-UTR-type I (3-UTRI) accumulate in a temperature-dependent manner. Here, we have investigated the translational efficiencies of both types of HSP70 transcripts at the different temperatures that the parasite encounters in the insect (26°C, normal temperature) or in the mammalian host (heat-shock temperatures). Interestingly, 3-UTRI-bearing transcripts (HSP70-I) were found associated with ribosomes in promastigotes at normal and heat-shock temperatures, whereas the HSP70-II transcripts appear to be preferentially translated at heat-shock temperatures but not at 26°C. We have analyzed the function of these UTRs in the translational control by use of plasmid constructs in which the CAT reporter gene was flanked by UTRs of the HSP70 genes. Unexpectedly, it was found that CAT transcripts with 3-UTRII bind to ribosomes at 26°C, and, indeed, the CAT protein is synthesized. A valid conclusion of these experiments was that both types of 3-UTRs are essential for translation of HSP70 mRNAs at heat shock temperatures, although the 3-UTRII is more efficient during severe heat shock (39°C). In addition, these results suggest that sequence region other than the 3-UTR of HSP70-II gene is involved in the translational silent state of HSP70-II transcripts at 26°C. Finally, a null mutant has been created by targeted disruption of both HSP70-II alleles. Remarkably, the ⌬HSP70 mutant synthesizes HSP70 at a lower rate than the wild-type parasites. Overall, our data suggest that the biological function of the HSP70-II gene is to top up HSP70 levels under conditions of stress.

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“…Most, if not all, proteinencoding genes are transcribed as polycistronic units (191,369). The expression of kinetoplastid genes is not controlled at the level of transcription initiation.…”

Section: Kinetoplast Dnamentioning

confidence: 99%

Pathogenesis of Chagas' Disease: Parasite Persistence and Autoimmunity

et al. 2011

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SUMMARY Acute Trypanosoma cruzi infections can be asymptomatic, but chronically infected individuals can die of Chagas' disease. The transfer of the parasite mitochondrial kinetoplast DNA (kDNA) minicircle to the genome of chagasic patients can explain the pathogenesis of the disease; in cases of Chagas' disease with evident cardiomyopathy, the kDNA minicircles integrate mainly into retrotransposons at several chromosomes, but the minicircles are also detected in coding regions of genes that regulate cell growth, differentiation, and immune responses. An accurate evaluation of the role played by the genotype alterations in the autoimmune rejection of self-tissues in Chagas' disease is achieved with the cross-kingdom chicken model system, which is refractory to T. cruzi infections. The inoculation of T. cruzi into embryonated eggs prior to incubation generates parasite-free chicks, which retain the kDNA minicircle sequence mainly in the macrochromosome coding genes. Crossbreeding transfers the kDNA mutations to the chicken progeny. The kDNA-mutated chickens develop severe cardiomyopathy in adult life and die of heart failure. The phenotyping of the lesions revealed that cytotoxic CD45, CD8 + γδ, and CD8α + T lymphocytes carry out the rejection of the chicken heart. These results suggest that the inflammatory cardiomyopathy of Chagas' disease is a genetically driven autoimmune disease.

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α‐ and β‐tubulin mRNAs of Trypanosoma cruzi originate from a single multicistronic transcript

Cited by 28 publications

References 29 publications

The L1Tc non-LTR retrotransposon of Trypanosoma cruzi contains an internal RNA-pol II-dependent promoter that strongly activates gene transcription and generates unspliced transcripts

The L1Tc non-LTR retrotransposon of Trypanosoma cruzi contains an internal RNA-pol II-dependent promoter that strongly activates gene transcription and generates unspliced transcripts

The Translational Efficiencies of the Two Leishmania infantum HSP70 mRNAs, Differing in Their 3′-Untranslated Regions, Are Affected by Shifts in the Temperature of Growth through Different Mechanisms

Pathogenesis of Chagas' Disease: Parasite Persistence and Autoimmunity

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