AUTHOR=Camponeschi Ilaria , Montanari Arianna , Beccaccioli Marzia , Reverberi Massimo , Mazzoni Cristina , Bianchi Michele M. 

TITLE=Light-Stress Response Mediated by the Transcription Factor KlMga2 in the Yeast Kluyveromyces lactis

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.705012

DOI=10.3389/fmicb.2021.705012

ISSN=1664-302X

ABSTRACT=<p>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 <italic>Kluyveromyces lactis</italic>. Yeast lacks specialized light-sensing proteins; however, <italic>Saccharomyces cerevisiae</italic> 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 <italic>K. lactis</italic>. 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 <italic>Kl</italic>Mga2. Alterations in growth rate, mitochondrial functioning, ROS metabolism, and fatty acid biosynthesis provide evidence that light was a source of stress in <italic>K. lactis</italic> and that <italic>Kl</italic>Mga2 had a role in the light-stress response. The involvement of <italic>Kl</italic>Msn2 and <italic>Kl</italic>Crz1 in light stress was also explored, but the latter showed no function in this response.</p>