title: ATP synthesis is coupled to rat liver mitochondrial RNA synthesis.
abstract: Rat liver mitochondria respond to changes in energy demand by modulating the amount of RNA synthesized. Coupled rat liver mitochondria were used to determine the relationship between mitochondrial respiration, ATP levels, and mitochondrial transcription. This system included oxidizable substrates (malate and glutamate) and constituents that could support both mitochondrial respiration and transcription. The respiratory inhibitor rotenone, phosphorylation inhibitor oligomycin, and the uncoupler of oxidative phosphorylation carbonyl-cyanide p-triflouromethoxyphehylhydrazone inhibited RNA synthesis. Addition of ADP stimulated mitochondrial transcription and peak RNA synthesis was observed at 1-2 mM ADP. At ADP concentrations above 2 mM, RNA synthesis decreased. These results demonstrate that mitochondrial transcription is tightly coupled to ATP levels.
authors.affiliation: Section on Brain Physiology and Metabolism, NIA, NIH, Bethesda, MD, USA.
authors.forename: S F
authors.initials: SF
authors.lastname: DasGupta
authors.forename: S I
authors.initials: SI
authors.lastname: Rapoport
authors.forename: M
authors.initials: M
authors.lastname: Gerschenson
authors.forename: E
authors.initials: E
authors.lastname: Murphy
authors.forename: G
authors.initials: G
authors.lastname: Fiskum
authors.forename: S J
authors.initials: SJ
authors.lastname: Russell
authors.forename: K
authors.initials: K
authors.lastname: Chandrasekaran
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000096:biosynthesis*; D000818:Animals; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D019069:Cell Respiration; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008930:Mitochondria, Liver / Q000378:metabolism*; D009840:Oligomycins / Q000494:pharmacology; D010101:Oxygen Consumption; D010766:Phosphorylation / Q000187:drug effects; D012313:RNA / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis; D000077278:RNA, Mitochondrial; D051381:Rats; D012402:Rotenone / Q000494:pharmacology; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects; D015533:Transcriptional Activation; D014475:Uncoupling Agents / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D009840:Oligomycins; D012333:RNA, Messenger; D000077278:RNA, Mitochondrial; D014475:Uncoupling Agents; D012402:Rotenone; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D000244:Adenosine Diphosphate; D012313:RNA; D000255:Adenosine Triphosphate