Differential Effects of Ethanol Consumption on Synthesis of Cytoplasmic and Mitochondrial Encoded Subunits of the ATP Synthase

Authors


  • This work was supported by a grant from the National Institute on Alcohol Abuse and Alcoholism AA 02887. W.B.C. was the recipient of a Predoctoral Fellowship under the National Research Service Award T32 CA 09422 from the National Cancer Institute.

Reprint requests: Dr. Carol C. Cunningham, Department of Biochemistry, Wake Forest University Medical Center, Medical Center Boulevard, Winston-Salem, NC 27157–1016.

Abstract

The relative concentrations of several subunits of the mitochondrial F0.F1-ATP synthase were determined in mitochondria and submitochondrial particles prepared from the livers of ethanol-fed and control rats. The polypeptides were separated by sodium dodecylsulfate-polyacrylamide gel electrophoresis and the stained gels were analyzed by densitometry for the relative concentrations of the ATP synthase subunits. A significant decrease in the relative concentration of the mitochondrial gene product, ATPase subunit 8, was observed in mitochondria and submitochondrial particles from ethanol-fed animals. The relative concentration of the other mitochondrial encoded ATPase subunit, ATPase 6, was also depressed, as confirmed in submitochondrial particles. In contrast, there were no significant ethanol-related depressions in subunits α, β, and OSCP of the F0. F1 or the adenine nucleotide carrier in intact mitochondria. These results demonstrate that ethanol consumption causes a decrease in the content of mitochondrial synthesized subunits 6 and 8 whereas no effect is exerted on the concentrations of nuclear gene products of the ATP synthase complex. Likewise, the adenine nucleotide transporter, also a nuclear gene product, is unaffected by ethanol consumption.

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