Incomplete sterols and hopanoids pathways in ciliates: Gene loss and acquisition during evolution as a source of biosynthetic genes
Polycyclic triterpenoids, such as sterols and hopanoids, are essential components of plasmatic membrane in eukaryotic organisms. Although it is generally assumed that ciliates do not synthesize sterols, and many of them are indeed auxotrophic, a large set of annotated genomic sequences and experimen...
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| Format: | Artículo |
| Language: | Inglés |
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Elsevier
2019
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| Online Access: | http://hdl.handle.net/20.500.12123/4316 https://www.sciencedirect.com/science/article/pii/S1055790314000451 https://doi.org/10.1016/j.ympev.2014.01.026 |
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| author | Tomazic, Mariela Luján Poklepovich Caride, Tomás Javier Nudel, Berta Clara Nusblat, Alejandro David |
| author_browse | Nudel, Berta Clara Nusblat, Alejandro David Poklepovich Caride, Tomás Javier Tomazic, Mariela Luján |
| author_facet | Tomazic, Mariela Luján Poklepovich Caride, Tomás Javier Nudel, Berta Clara Nusblat, Alejandro David |
| author_sort | Tomazic, Mariela Luján |
| collection | INTA Digital |
| description | Polycyclic triterpenoids, such as sterols and hopanoids, are essential components of plasmatic membrane in eukaryotic organisms. Although it is generally assumed that ciliates do not synthesize sterols, and many of them are indeed auxotrophic, a large set of annotated genomic sequences and experimental data from recently studied organisms indicate that they can carry putative genes and respond to the presence/absence of precursors in various ways. The pre-squalene pathway, for instance, is largely present in all sequenced ciliates except in Ichthyophthirius multifiliis; although Paramecium tetraurelia lacks the squalene synthase and Oxytricha trifallax the squalene hopene synthase, in addition to the former. On the other hand, the post-squalene pathway, requiring oxygen in several steps, is mostly incomplete in all ciliates analyzed. Nevertheless, a number of predicted genes, with high sequence similarity to C-4 methyl oxidase/s, C-14 demethylase, C-5 and C-7 desaturases and C-24 reductase of sterols are found in Tetrahymena and Paramecium, and scattered in other Stichotrichia ciliates. Moreover, several of these sequences are present in multiples paralogs, like the C-7 desaturase in Paramecium, that carries six versions of the only one present in Tetrahymena.
The phylogenetic analyses suggest a mixed origin for the genes involved in the biosynthesis of sterols and surrogates in this phylum; while the genes encoding enzymes of the pre-squalene pathway are most likely of bacterial origin, those involved in the post-squalene pathway, including the processing of sterols obtained from the environment, may have been partially retained or acquired indistinctly from lower eukaryotes or prokaryotes. This particular combination of diverse gene/s acquisition patterns allows for survival in conditions of poor oxygen availability, in which tetrahymanol and other hopanoids may be advantageous, but also conditions of excess oxygen availability and abundant sterols, in which the latter are preferentially phagocyte, and/or transformed. Furthermore, the possibility that some of the genes involved in sterol metabolism may have another biological function in the most studied ciliate T. thermophila, was also explored. |
| format | Artículo |
| id | INTA4316 |
| institution | Instituto Nacional de Tecnología Agropecuaria (INTA -Argentina) |
| language | Inglés |
| publishDate | 2019 |
| publishDateRange | 2019 |
| publishDateSort | 2019 |
| publisher | Elsevier |
| publisherStr | Elsevier |
| record_format | dspace |
| spelling | INTA43162024-03-27T19:14:35Z Incomplete sterols and hopanoids pathways in ciliates: Gene loss and acquisition during evolution as a source of biosynthetic genes Tomazic, Mariela Luján Poklepovich Caride, Tomás Javier Nudel, Berta Clara Nusblat, Alejandro David Esteroles Genética Genes Tetrahymena Paramecium Triterpenóidos Sterols Genetics Triterpenoids Hopanoids Ciliates Polycyclic triterpenoids, such as sterols and hopanoids, are essential components of plasmatic membrane in eukaryotic organisms. Although it is generally assumed that ciliates do not synthesize sterols, and many of them are indeed auxotrophic, a large set of annotated genomic sequences and experimental data from recently studied organisms indicate that they can carry putative genes and respond to the presence/absence of precursors in various ways. The pre-squalene pathway, for instance, is largely present in all sequenced ciliates except in Ichthyophthirius multifiliis; although Paramecium tetraurelia lacks the squalene synthase and Oxytricha trifallax the squalene hopene synthase, in addition to the former. On the other hand, the post-squalene pathway, requiring oxygen in several steps, is mostly incomplete in all ciliates analyzed. Nevertheless, a number of predicted genes, with high sequence similarity to C-4 methyl oxidase/s, C-14 demethylase, C-5 and C-7 desaturases and C-24 reductase of sterols are found in Tetrahymena and Paramecium, and scattered in other Stichotrichia ciliates. Moreover, several of these sequences are present in multiples paralogs, like the C-7 desaturase in Paramecium, that carries six versions of the only one present in Tetrahymena. The phylogenetic analyses suggest a mixed origin for the genes involved in the biosynthesis of sterols and surrogates in this phylum; while the genes encoding enzymes of the pre-squalene pathway are most likely of bacterial origin, those involved in the post-squalene pathway, including the processing of sterols obtained from the environment, may have been partially retained or acquired indistinctly from lower eukaryotes or prokaryotes. This particular combination of diverse gene/s acquisition patterns allows for survival in conditions of poor oxygen availability, in which tetrahymanol and other hopanoids may be advantageous, but also conditions of excess oxygen availability and abundant sterols, in which the latter are preferentially phagocyte, and/or transformed. Furthermore, the possibility that some of the genes involved in sterol metabolism may have another biological function in the most studied ciliate T. thermophila, was also explored. Instituto de Patobiología Fil: Tomazic, Mariela Luján. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; Argentina Fil: Poklépovich Caride, Tomás Javier. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología Industrial y Biotecnología; Argentina. Fil: Nudel, Berta Clara. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología Industrial y Biotecnología; Argentina Fil: Nusblat, Alejandro David. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología Industrial y Biotecnología; Argentina 2019-01-23T13:30:59Z 2019-01-23T13:30:59Z 2014-05 info:ar-repo/semantics/artículo info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://hdl.handle.net/20.500.12123/4316 https://www.sciencedirect.com/science/article/pii/S1055790314000451 1055-7903 https://doi.org/10.1016/j.ympev.2014.01.026 eng info:eu-repo/semantics/restrictedAccess application/pdf Elsevier Molecular Phylogenetics and Evolution 74 : 122-134 (May 2014) |
| spellingShingle | Esteroles Genética Genes Tetrahymena Paramecium Triterpenóidos Sterols Genetics Triterpenoids Hopanoids Ciliates Tomazic, Mariela Luján Poklepovich Caride, Tomás Javier Nudel, Berta Clara Nusblat, Alejandro David Incomplete sterols and hopanoids pathways in ciliates: Gene loss and acquisition during evolution as a source of biosynthetic genes |
| title | Incomplete sterols and hopanoids pathways in ciliates: Gene loss and acquisition during evolution as a source of biosynthetic genes |
| title_full | Incomplete sterols and hopanoids pathways in ciliates: Gene loss and acquisition during evolution as a source of biosynthetic genes |
| title_fullStr | Incomplete sterols and hopanoids pathways in ciliates: Gene loss and acquisition during evolution as a source of biosynthetic genes |
| title_full_unstemmed | Incomplete sterols and hopanoids pathways in ciliates: Gene loss and acquisition during evolution as a source of biosynthetic genes |
| title_short | Incomplete sterols and hopanoids pathways in ciliates: Gene loss and acquisition during evolution as a source of biosynthetic genes |
| title_sort | incomplete sterols and hopanoids pathways in ciliates gene loss and acquisition during evolution as a source of biosynthetic genes |
| topic | Esteroles Genética Genes Tetrahymena Paramecium Triterpenóidos Sterols Genetics Triterpenoids Hopanoids Ciliates |
| url | http://hdl.handle.net/20.500.12123/4316 https://www.sciencedirect.com/science/article/pii/S1055790314000451 https://doi.org/10.1016/j.ympev.2014.01.026 |
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