Expression of the ADP/ATP carrier encoding genes in aerobic yeasts; phenotype of an ADP/ATP carrier deletion mutant of Schizosaccharomyces pombe

The expression of a key mitochondrial membrane component, the ADP/ATP carri er, was investigated in two aerobic yeast species, Kluyveromyces lactis and Schizosaccharomyces pombe. Although the two species differ very much in th eir respiratory capacity, the expression of the carrier in both yeast speci es was decreased under partially anaerobic conditions and was induced by no nfermentable carbon sources. The single ADP/ATP carrier encoding gene was d eleted in S. pambe. The null mutant exhibits impaired growth properties, es pecially when cultivated at reduced oxygen tension, and is unable to grow o n a nonfermentable carbon source. Our results suggest that the inability of K. lactis and S. pombe to grow under anaerobic conditions can be related i n part to the absence of a functional ADP/ATP carrier due to repression of the corresponding gene expression. (C) 1999 Elsevier Science B.V. All right s reserved.