Allele specific expression of the Mgi(-) phenotype on disruption of the F-1-ATPase delta-subunit gene in Kluyveromyces lactis

作者：Han**ro PM^*; Chen XJ; Clark Walker GD

来源：Current Genetics, 1998, 33(1): 46-51.

DOI：10.1007/s002940050307

• Kluyveromyces lactis
• mitochondrial genome integrity
• F-1-ATPase delta-subunit gene
• ATP delta-disruption

Kluyveromyces lactis is a petite-negative yeast that does not form viable mitochondrial genome-deletion mutants (petites) when treated with DNA-targeting drugs. Loss of mtDNA is lethal for this yeast but mutations at three loci termed MG1, for mitochondrial genome integrity, can suppress this lethality. The three loci encode the alpha-, beta- and gamma-subunits of mitochondrial F-1-ATPase. In this study we report the isolation and characterization of the K1ATP delta gene encoding the delta-subunit of F-1-ATPase. The deduced protein contains 158 amino acids showing 72% identity to the protein from Saccharomyces cerevisiae and a putative mitochondrial targeting sequence of 23 amino acids. Disruption of the gene causes cells to become respiratory deficient while the introduction of ATP delta from S. cerevisiae restores growth on glycerol, Cells with a disrupted ATP delta gene, like strains with disruptions of alpha-, beta- and gamma-F-1-subunits, do not produce petite mutants when treated with ethidium bromide. However, unlike strains with disruptions in the three largest F-1-subunits, disruption of ATP delta in the presence of some mgi alleles does not abolish the Mgi(-) phenotype. By contrast, elimination of ATP delta in other mgi strains removes resistance to ethidium bromide and rho(0) mutants are not formed, Hence the ATP delta subunit of F-1-ATPase, while not mandatory for a Mgi(-) phenotype,aids some mgi alleles in suppressing rho(0) lethality.

• 出版日期1998-1