title: Chromophore-Assisted Light Inactivation of Mitochondrial Electron Transport Chain Complex II in Caenorhabditis elegans.
abstract: Mitochondria play critical roles in meeting cellular energy demand, in cell death, and in reactive oxygen species (ROS) and stress signaling. Most Caenorhabditis elegans loss-of-function (lf) mutants in nuclear-encoded components of the respiratory chain are non-viable, emphasizing the importance of respiratory function. Chromophore-Assisted Light Inactivation (CALI) using genetically-encoded photosensitizers provides an opportunity to determine how individual respiratory chain components contribute to physiology following acute lf. As proof-of-concept, we expressed the 'singlet oxygen generator' miniSOG as a fusion with the SDHC subunit of respiratory complex II, encoded by mev-1 in C. elegans, using Mos1-mediated Single Copy Insertion. The resulting mev-1::miniSOG transgene complemented mev-1 mutant phenotypes in kn1 missense and tm1081(lf) deletion mutants. Complex II activity was inactivated by blue light in mitochondria from strains expressing active miniSOG fusions, but not those from inactive fusions. Moreover, light-inducible phenotypes in vivo demonstrated that complex II activity is important under conditions of high energy demand, and that specific cell types are uniquely susceptible to loss of complex II. In conclusion, miniSOG-mediated CALI is a novel genetic platform for acute inactivation of respiratory chain components. Spatio-temporally controlled ROS generation will expand our understanding of how the respiratory chain and mitochondrial ROS influence whole organism physiology.
authors.affiliation: University of Rochester Medical Center, Department of Anesthesiology, Rochester, 14642, United States of America.|University of Rochester Medical Center, Department of Pharmacology and Physiology, Rochester, 14642, United States of America.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Wojtovich
authors.affiliation: University of Rochester Medical Center, Department of Anesthesiology, Rochester, 14642, United States of America.
authors.forename: Alicia Y
authors.initials: AY
authors.lastname: Wei
authors.affiliation: University of Rochester Medical Center, Department of Medicine, Rochester, 14642, United States of America.
authors.forename: Teresa A
authors.initials: TA
authors.lastname: Sherman
authors.affiliation: University of Rochester Medical Center, Department of Imaging Sciences, Rochester, 14642, United States of America.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Foster
authors.affiliation: University of Rochester Medical Center, Department of Pharmacology and Physiology, Rochester, 14642, United States of America.|University of Rochester Medical Center, Department of Medicine, Rochester, 14642, United States of America.
authors.forename: Keith
authors.initials: K
authors.lastname: Nehrke
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000378:metabolism; D061885:Chromophore-Assisted Light Inactivation; D052284:Clutch Size; D042963:Electron Transport Complex II / Q000235:genetics* / Q000378:metabolism; D055785:Gene Knockdown Techniques; D005816:Genetic Complementation Test; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D020125:Mutation, Missense; D062308:Optogenetics
chemical_list: D029742:Caenorhabditis elegans Proteins; C478189:respiratory complex II; D042963:Electron Transport Complex II