Program in Gene Function and Expression; Program in Molecular Medicine
Medical Subject Headings
Animals; Caenorhabditis elegans; Cell Compartmentation; Chaperonin 60; Endoplasmic Reticulum; Energy Metabolism; Gene Expression Regulation; HSP70 Heat-Shock Proteins; Heat-Shock Response; Intracellular Membranes; Macromolecular Substances; Mitochondria; Molecular Chaperones; Oxidative Stress; Protein Folding; RNA Interference; Transcriptional Activation
Genetics and Genomics
Protein folding in the mitochondria is assisted by nuclear-encoded compartment-specific chaperones but regulation of the expression of their encoding genes is poorly understood. We found that the mitochondrial matrix HSP70 and HSP60 chaperones, encoded by the Caenorhabditis elegans hsp-6 and hsp-60 genes, were selectively activated by perturbations that impair assembly of multi-subunit mitochondrial complexes or by RNAi of genes encoding mitochondrial chaperones or proteases, which lead to defective protein folding and processing in the organelle. hsp-6 and hsp-60 induction was specific to perturbed mitochondrial protein handling, as neither heat-shock nor endoplasmic reticulum stress nor manipulations that impair mitochondrial steps in intermediary metabolism or ATP synthesis activated the mitochondrial chaperone genes. These observations support the existence of a mitochondrial unfolded protein response that couples mitochondrial chaperone gene expression to changes in the protein handling environment in the organelle.
Rights and Permissions
Citation: J Cell Sci. 2004 Aug 15;117(Pt 18):4055-66. Epub 2004 Jul 27. Link to article on publisher's site