Gene identification and functional characterization of a Δ12 fatty acid desaturase in Tetrahymena thermophila and its influence in homeoviscous adaptation to low temperature.

Autor: Sanchez Granel ML; Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Nanobiotecnología (NANOBIOTEC), Facultad de Farmacia y Bioquímica, Junín, 956, C1113AAD Ciudad Autónoma de Buenos Aires, Argentina., Cánepa C; Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones Biomédicas en Retrovirus y SIDA, Facultad de Medicina, Paraguay 2155, C1121ABG Ciudad Autónoma de Buenos Aires, Argentina., Cid NG; Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Nanobiotecnología (NANOBIOTEC), Facultad de Farmacia y Bioquímica, Junín, 956, C1113AAD Ciudad Autónoma de Buenos Aires, Argentina., Navarro JC; Instituto de Acuicultura Torre de la Sal, CSIC (IATS-CSIC), Ribera de Cabanes, 12595, Castellón, Spain., Monroig Ó; Instituto de Acuicultura Torre de la Sal, CSIC (IATS-CSIC), Ribera de Cabanes, 12595, Castellón, Spain., Verstraeten SV; Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Química y Fisicoquímica Biológicas (IQUIFIB), Facultad de Farmacia y Bioquímica, Paraguay 2155, C1121ABG Ciudad Autónoma de Buenos Aires, Argentina., Nudel CB; Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Nanobiotecnología (NANOBIOTEC), Facultad de Farmacia y Bioquímica, Junín, 956, C1113AAD Ciudad Autónoma de Buenos Aires, Argentina., Nusblat AD; Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Nanobiotecnología (NANOBIOTEC), Facultad de Farmacia y Bioquímica, Junín, 956, C1113AAD Ciudad Autónoma de Buenos Aires, Argentina. Electronic address: anusblat@ffyb.uba.ar.
Jazyk: angličtina
Zdroj: Biochimica et biophysica acta. Molecular and cell biology of lipids [Biochim Biophys Acta Mol Cell Biol Lipids] 2019 Nov; Vol. 1864 (11), pp. 1644-1655. Date of Electronic Publication: 2019 Aug 14.
DOI: 10.1016/j.bbalip.2019.08.003
Abstrakt: 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.
(Copyright © 2019 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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