Light-Stress Response Mediated by the Transcription Factor Kl Mga2 in the Yeast Kluyveromyces lactis

Ilaria Camponeschi; Arianna Montanari; Marzia Beccaccioli; Massimo Reverberi; Cristina Mazzoni; Michele M Bianchi

doi:10.3389/fmicb.2021.705012

Light-Stress Response Mediated by the Transcription Factor Kl Mga2 in the Yeast Kluyveromyces lactis

Front Microbiol. 2021 Jul 14:12:705012. doi: 10.3389/fmicb.2021.705012. eCollection 2021.

Authors

Ilaria Camponeschi¹, Arianna Montanari¹, Marzia Beccaccioli², Massimo Reverberi², Cristina Mazzoni¹, Michele M Bianchi¹

Affiliations

¹ Department of Biology and Biotechnology 'C. Darwin', Sapienza University of Rome, Rome, Italy.
² Department of Environmental Biology, Sapienza University of Rome, Rome, Italy.

Abstract

In unicellular organisms like yeasts, which do not have specialized tissues for protection against environmental challenges, the presence of cellular mechanisms to respond and adapt to stress conditions is fundamental. In this work, we aimed to investigate the response to environmental light in Kluyveromyces lactis. Yeast lacks specialized light-sensing proteins; however, Saccharomyces cerevisiae has been reported to respond to light by increasing hydrogen peroxide level and triggering nuclear translocation of Msn2. This is a stress-sensitive transcription factor also present in K. lactis. To investigate light response in this yeast, we analyzed the different phenotypes generated by the deletion of the hypoxia responsive and lipid biosynthesis transcription factor KlMga2. Alterations in growth rate, mitochondrial functioning, ROS metabolism, and fatty acid biosynthesis provide evidence that light was a source of stress in K. lactis and that KlMga2 had a role in the light-stress response. The involvement of KlMsn2 and KlCrz1 in light stress was also explored, but the latter showed no function in this response.

Keywords: ROS; desaturase; fungi; lipid; membrane.