Biogenesis of mitochondria. The effects of physiological and genetic manipulation of Saccharomyces cerevisiae on the mitochondrial transport systems for tricarboxylate-cycle anions

Abstract

1. Kinetic and equilibrium parameters for the uptake of l-malate, succinate, citrate and α-oxoglutarate by fully functional mitochondria of Saccharomyces cerevisiae were determined. 2. The uptake of l-malate and succinate is mediated by a common carrier, and two other distinct carriers mediate the uptake of citrate and α-oxoglutarate. 3. The properties of the carrier systems for l-malate, succinate and citrate closely resemble those of mammalian mitochondria, but the α-oxoglutarate carrier differs from the mammalian system in minor respects. 4. The composition of the yeast mitochondria was extensively manipulated by (a) anaerobiosis, (b) catabolite repression, (c) inhibition of mitochondrial protein synthesis and (d) elimination of mitochondrial DNA by mutation. 5. The carrier systems for l-malate, succinate, citrate and α-oxoglutarate are essentially similar in the five different types of mitochondria. 6. It is concluded that all the protein components of the carrier systems for l-malate, succinate, citrate and α-oxoglutarate are coded by nuclear genes and synthesized extramitochondrially by cell-sap ribosomes.