title: Reduction of protein translation and activation of autophagy protect against PINK1 pathogenesis in Drosophila melanogaster.
abstract: Mutations in PINK1 and Parkin cause familial, early onset Parkinson's disease. In Drosophila melanogaster, PINK1 and Parkin mutants show similar phenotypes, such as swollen and dysfunctional mitochondria, muscle degeneration, energy depletion, and dopaminergic (DA) neuron loss. We previously showed that PINK1 and Parkin genetically interact with the mitochondrial fusion/fission pathway, and PINK1 and Parkin were recently proposed to form a mitochondrial quality control system that involves mitophagy. However, the in vivo relationships among PINK1/Parkin function, mitochondrial fission/fusion, and autophagy remain unclear; and other cellular events critical for PINK1 pathogenesis remain to be identified. Here we show that PINK1 genetically interacted with the protein translation pathway. Enhanced translation through S6K activation significantly exacerbated PINK1 mutant phenotypes, whereas reduction of translation showed suppression. Induction of autophagy by Atg1 overexpression also rescued PINK1 mutant phenotypes, even in the presence of activated S6K. Downregulation of translation and activation of autophagy were already manifested in PINK1 mutant, suggesting that they represent compensatory cellular responses to mitochondrial dysfunction caused by PINK1 inactivation, presumably serving to conserve energy. Interestingly, the enhanced PINK1 mutant phenotype in the presence of activated S6K could be fully rescued by Parkin, apparently in an autophagy-independent manner. Our results reveal complex cellular responses to PINK1 inactivation and suggest novel therapeutic strategies through manipulation of the compensatory responses.
authors.affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Song
authors.initials: S
authors.lastname: Liu
authors.forename: Bingwei
authors.initials: B
authors.lastname: Lu
mesh_terms: D000818:Animals; D001343:Autophagy; D000071189:Autophagy-Related Protein-1 Homolog; D004195:Disease Models, Animal; D015536:Down-Regulation; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D010300:Parkinson Disease / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D014176:Protein Biosynthesis; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism; D000099202:PTEN-Induced Putative Kinase
chemical_list: D000071189:Autophagy-Related Protein-1 Homolog; D029721:Drosophila Proteins; D017346:Protein Serine-Threonine Kinases; D044767:Ubiquitin-Protein Ligases; C518074:Atg1 protein, Drosophila; C534484:PINK1 protein, Drosophila; D000099202:PTEN-Induced Putative Kinase; C487430:park protein, Drosophila