Gene identification and functional characterization of a Δ12 fatty acid desaturase in Tetrahymena thermophila and its influence in homeoviscous adaptation to low temperature
| Autor: | Nicolas G. Cid, Juan Carlos Navarro, Sandra V. Verstraeten, María Luz Sanchez Granel, Clara B. Nudel, Camila Cánepa, Alejandro D. Nusblat, Óscar Monroig |
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| Přispěvatelé: | Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina), Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina), Universidad de Buenos Aires, Navarro, Juan Carlos [0000-0001-6976-6686], Monroig, Óscar [0000-0001-8712-0440], Navarro, Juan Carlos, Monroig, Óscar |
| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
0301 basic medicine Fatty Acid Desaturases Membrane lipids 010603 evolutionary biology 01 natural sciences Tetrahymena thermophila Ciencias Biológicas Δ12 fatty acid desaturase 03 medical and health sciences Biología Celular Microbiología Fatty acid desaturases Membrane fluidity Molecular Biology Gene knockout Phospholipids chemistry.chemical_classification Membranes biology Chemistry Cold-Shock Response Tetrahymena Homeoviscous adaptation Cell Biology biology.organism_classification Triterpenes Cold Temperature 030104 developmental biology Fatty acid desaturase Biochemistry Gene Knockdown Techniques biology.protein Fatty Acids Unsaturated Heterologous expression Cold stress CIENCIAS NATURALES Y EXACTAS Polyunsaturated fatty acid |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| ISSN: | 1122-0120 |
| Popis: | Homeoviscous adaptation in poikilotherms is based in the regulation of the level of desaturation of fatty acids, variation in phospholipids head groups and sterol content in the membrane lipids, in order to maintain the membrane fluidity in response to changes in environmental temperature. Increased proportion of unsaturated fatty acids is thought to be the main response to low-temperature acclimation, which is mostly achieved by fatty acid desaturases. Genome analysis of the ciliate Tetrahymena thermophila and a gene knockout approach has allowed us to identify one Δ12 FAD and to study its activity in the original host and in a yeast heterologous expression system. The “PUFA index” -relative content of polyunsaturated fatty acids compared to the sum of saturated and monounsaturated fatty acid content- was ~57% lower at 15 °C and 35 °C in the Δ12 FAD gene knockout strain (KOΔ12) compared to WT strain. We characterized the role of T. thermophila Δ12 FAD on homeoviscous adaptation and analyzed its involvement in cellular growth, cold stress response, and membrane fluidity, as well as its expression pattern during temperature shifts. Although these alterations allowed normal growth in the KOΔ12 strain at 30 °C or higher temperatures, growth was impaired at temperatures of 20 °C or lower, where homeoviscous adaptation is impaired. These results stress the importance of Δ12 FAD in the regulation of cold adaptation processes, as well as the suitability of T. thermophila as a valuable model to investigate the regulation of membrane lipids and evolutionary conservation and divergence of the underlying mechanisms. This work was supported by the Consejo Nacional de Investigaciones Científicas y Técnicas, PIP 11220120100213; Ministerio de Ciencia, Tecnología e Innovación Productiva, PICT 2013–0701, and Universidad de Buenos Aires, UBACYT 20020130100680BA. Further funding was obtained through a Proyecto Intramural Especial of CSIC (201840I016) awarded to OM. |
| Databáze: | OpenAIRE |
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