title: Activation of Autophagy by Metals in Chlamydomonas reinhardtii.
abstract: Autophagy is an intracellular self-degradation pathway by which eukaryotic cells recycle their own material in response to specific stress conditions. Exposure to high concentrations of metals causes cell damage, although the effect of metal stress on autophagy has not been explored in photosynthetic organisms. In this study, we investigated the effect of metal excess on autophagy in the model unicellular green alga Chlamydomonas reinhardtii. We show in cells treated with nickel an upregulation of ATG8 that is independent of CRR1, a global regulator of copper signaling in Chlamydomonas. A similar effect on ATG8 was observed with copper and cobalt but not with cadmium or mercury ions. Transcriptome sequencing data revealed an increase in the abundance of the protein degradation machinery, including that responsible for autophagy, and a substantial overlap of that increased abundance with the hydrogen peroxide response in cells treated with nickel ions. Thus, our results indicate that metal stress triggers autophagy in Chlamydomonas and suggest that excess nickel may cause oxidative damage, which in turn activates degradative pathways, including autophagy, to clear impaired components and recover cellular homeostasis.
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Sevilla, Seville, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Pérez-Martín
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, California, USA.
authors.forename: Crysten E
authors.initials: CE
authors.lastname: Blaby-Haas
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Sevilla, Seville, Spain.
authors.forename: María Esther
authors.initials: ME
authors.lastname: Pérez-Pérez
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Sevilla, Seville, Spain.
authors.forename: Ascensión
authors.initials: A
authors.lastname: Andrés-Garrido
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, California, USA.
authors.forename: Ian K
authors.initials: IK
authors.lastname: Blaby
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, California, USA Institute for Genomics and Proteomics, University of California, Los Angeles, California, USA.
authors.forename: Sabeeha S
authors.initials: SS
authors.lastname: Merchant
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Sevilla, Seville, Spain crespo@ibvf.csic.es.
authors.forename: José L
authors.initials: JL
authors.lastname: Crespo
mesh_terms: D001343:Autophagy; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism; D016825:Chlamydomonas reinhardtii / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D019216:Metals, Heavy / Q000494:pharmacology / Q000633:toxicity*; D018384:Oxidative Stress; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D059467:Transcriptome
chemical_list: D027682:Cation Transport Proteins; D019216:Metals, Heavy; D010940:Plant Proteins