title: The import of the transcription factor STAT3 into mitochondria depends on GRIM-19, a component of the electron transport chain.
abstract: The signal transducer and activator of transcription 3 (STAT3), a nuclear transcription factor, is also present in mitochondria and regulates cellular respiration in a transcriptional-independent manner. The mechanism of STAT3 import into mitochondria remains obscure. In this report we show that mitochondrial-localized STAT3 resides in the inner mitochondrial membrane. In vitro import studies show that the gene associated with retinoid interferon induced cell mortality 19 (GRIM-19), a complex I subunit that acts as a chaperone to recruit STAT3 into mitochondria. In addition, GRIM-19 enhances the integration of STAT3 into complex I. A S727A mutation in STAT3 reduces its import and assembly even in the presence of GRIM-19. Together, our studies unveil a novel chaperone function for GRIM-19 in the recruitment of STAT3 into mitochondria.
authors.affiliation: Department of Biochemistry, University of Hyderabad, Hyderabad 500046, India.
authors.forename: Prasad
authors.initials: P
authors.lastname: Tammineni
authors.forename: Chandrashekhar
authors.initials: C
authors.lastname: Anugula
authors.forename: Fareed
authors.initials: F
authors.lastname: Mohammed
authors.forename: Murari
authors.initials: M
authors.lastname: Anjaneyulu
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Larner
authors.forename: Naresh Babu Venkata
authors.initials: NB
authors.lastname: Sepuri
mesh_terms: D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D001692:Biological Transport; D004579:Electron Transport; D042967:Electron Transport Complex I / Q000378:metabolism*; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D008928:Mitochondria / Q000378:metabolism; D051336:Mitochondrial Membranes / Q000378:metabolism*; D008954:Models, Biological; D018832:Molecular Chaperones / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D010766:Phosphorylation; D011817:Rabbits; D051381:Rats; D050796:STAT3 Transcription Factor / Q000378:metabolism*
chemical_list: D051017:Apoptosis Regulatory Proteins; D018832:Molecular Chaperones; D050796:STAT3 Transcription Factor; D009247:NADH, NADPH Oxidoreductases; C439057:NDUFA13 protein, human; D042967:Electron Transport Complex I; C580719:Ndufa13 protein, rat