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Novel Features of a PIWI-Like Protein Homolog in the Parasitic Protozoan Leishmania

In contrast to nearly all eukaryotes, the Old World Leishmania species L. infantum and L. major lack the bona fide RNAi machinery genes. Interestingly, both Leishmania genomes code for an atypical Argonaute-like protein that possesses a PIWI domain but lacks the PAZ domain found in Argonautes from R...

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Autores principales: Padmanabhan, Prasad K., Dumas, Carole, Samant, Mukesh, Rochette, Annie, Simard, Martin J., Papadopoulou, Barbara
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3528672/
https://www.ncbi.nlm.nih.gov/pubmed/23285111
http://dx.doi.org/10.1371/journal.pone.0052612
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author Padmanabhan, Prasad K.
Dumas, Carole
Samant, Mukesh
Rochette, Annie
Simard, Martin J.
Papadopoulou, Barbara
author_facet Padmanabhan, Prasad K.
Dumas, Carole
Samant, Mukesh
Rochette, Annie
Simard, Martin J.
Papadopoulou, Barbara
author_sort Padmanabhan, Prasad K.
collection PubMed
description In contrast to nearly all eukaryotes, the Old World Leishmania species L. infantum and L. major lack the bona fide RNAi machinery genes. Interestingly, both Leishmania genomes code for an atypical Argonaute-like protein that possesses a PIWI domain but lacks the PAZ domain found in Argonautes from RNAi proficient organisms. Using sub-cellular fractionation and confocal fluorescence microscopy, we show that unlike other eukaryotes, the PIWI-like protein is mainly localized in the single mitochondrion in Leishmania. To predict PIWI function, we generated a knockout mutant for the PIWI gene in both L. infantum (Lin) and L. major species by double-targeted gene replacement. Depletion of PIWI has no effect on the viability of insect promastigote forms but leads to an important growth defect of the mammalian amastigote lifestage in vitro and significantly delays disease pathology in mice, consistent with a higher expression of the PIWI transcript in amastigotes. Moreover, amastigotes lacking PIWI display a higher sensitivity to apoptosis inducing agents than wild type parasites, suggesting that PIWI may be a sensor for apoptotic stimuli. Furthermore, a whole-genome DNA microarray analysis revealed that loss of LinPIWI in Leishmania amastigotes affects mostly the expression of specific subsets of developmentally regulated genes. Several transcripts encoding surface and membrane-bound proteins were found downregulated in the LinPIWI((−/−)) mutant whereas all histone transcripts were upregulated in the null mutant, supporting the possibility that PIWI plays a direct or indirect role in the stability of these transcripts. Although our data suggest that PIWI is not involved in the biogenesis or the stability of small noncoding RNAs, additional studies are required to gain further insights into the role of this protein on RNA regulation and amastigote development in Leishmania.
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spelling pubmed-35286722013-01-02 Novel Features of a PIWI-Like Protein Homolog in the Parasitic Protozoan Leishmania Padmanabhan, Prasad K. Dumas, Carole Samant, Mukesh Rochette, Annie Simard, Martin J. Papadopoulou, Barbara PLoS One Research Article In contrast to nearly all eukaryotes, the Old World Leishmania species L. infantum and L. major lack the bona fide RNAi machinery genes. Interestingly, both Leishmania genomes code for an atypical Argonaute-like protein that possesses a PIWI domain but lacks the PAZ domain found in Argonautes from RNAi proficient organisms. Using sub-cellular fractionation and confocal fluorescence microscopy, we show that unlike other eukaryotes, the PIWI-like protein is mainly localized in the single mitochondrion in Leishmania. To predict PIWI function, we generated a knockout mutant for the PIWI gene in both L. infantum (Lin) and L. major species by double-targeted gene replacement. Depletion of PIWI has no effect on the viability of insect promastigote forms but leads to an important growth defect of the mammalian amastigote lifestage in vitro and significantly delays disease pathology in mice, consistent with a higher expression of the PIWI transcript in amastigotes. Moreover, amastigotes lacking PIWI display a higher sensitivity to apoptosis inducing agents than wild type parasites, suggesting that PIWI may be a sensor for apoptotic stimuli. Furthermore, a whole-genome DNA microarray analysis revealed that loss of LinPIWI in Leishmania amastigotes affects mostly the expression of specific subsets of developmentally regulated genes. Several transcripts encoding surface and membrane-bound proteins were found downregulated in the LinPIWI((−/−)) mutant whereas all histone transcripts were upregulated in the null mutant, supporting the possibility that PIWI plays a direct or indirect role in the stability of these transcripts. Although our data suggest that PIWI is not involved in the biogenesis or the stability of small noncoding RNAs, additional studies are required to gain further insights into the role of this protein on RNA regulation and amastigote development in Leishmania. Public Library of Science 2012-12-21 /pmc/articles/PMC3528672/ /pubmed/23285111 http://dx.doi.org/10.1371/journal.pone.0052612 Text en © 2012 Padmanabhan et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Padmanabhan, Prasad K.
Dumas, Carole
Samant, Mukesh
Rochette, Annie
Simard, Martin J.
Papadopoulou, Barbara
Novel Features of a PIWI-Like Protein Homolog in the Parasitic Protozoan Leishmania
title Novel Features of a PIWI-Like Protein Homolog in the Parasitic Protozoan Leishmania
title_full Novel Features of a PIWI-Like Protein Homolog in the Parasitic Protozoan Leishmania
title_fullStr Novel Features of a PIWI-Like Protein Homolog in the Parasitic Protozoan Leishmania
title_full_unstemmed Novel Features of a PIWI-Like Protein Homolog in the Parasitic Protozoan Leishmania
title_short Novel Features of a PIWI-Like Protein Homolog in the Parasitic Protozoan Leishmania
title_sort novel features of a piwi-like protein homolog in the parasitic protozoan leishmania
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3528672/
https://www.ncbi.nlm.nih.gov/pubmed/23285111
http://dx.doi.org/10.1371/journal.pone.0052612
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