The mitochondrial small heat-shock protein protects NADH:ubiquinone oxidoreductase of the electron transport chain during heat stress in plants.
Functional inactivation of the mitochondrial small heat-shock protein (lmw Hsp) in submitochondrial vesicles using protein-specific antibodies indicated that this protein protects NADH:ubiquinone oxidoreductase (complex I), and consequently electron transport from complex I to cytochrome c:O2 oxidoreductase (complex IV). Lmw Hsp function completely accounted for heat acclimation of complex I electron transport in pre-heat-stressed plants. Addition of purified lmw Hsp to submitochondrial vesicles lacking this Hsp increased complex I electron transport rates 100% in submitochondrial vesicles assayed at high temperatures. These results indicate that production of the mitochondrial lmw Hsp is an important adaptation to heat stress in plants.
Department of Biology, University of Charleston, SC 29424, USA. cadowns@technologist.com
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D004579:Electron Transport / Q000502:physiology; D005638:Fruit / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000302:isolation & purification / Q000494:pharmacology / Q000502:physiology*; D006358:Hot Temperature; D008928:Mitochondria / Q000378:metabolism; D009097:Multienzyme Complexes / Q000378:metabolism; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D010085:Oxidative Phosphorylation; D010940:Plant Proteins / Q000302:isolation & purification / Q000494:pharmacology / Q000502:physiology*
D006360:Heat-Shock Proteins; C110899:LMW heat shock protein, Fragaria x ananassa; D009097:Multienzyme Complexes; D010940:Plant Proteins; C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases; D016660:NAD(P)H Dehydrogenase (Quinone)