Characterization of a second nuclear gene, AEP1, required for expression of the mitochondrial OLI1 gene in Saccharomyces cerevisiae

• Published in: Current genetics 1993-07, Vol.24 (1-2), p.126-135
• Main Authors: Payne, M.J. (Monash Univ. Clayton, VIC (Australia). Dept. Biochemistry), Finnegan, P.M, Smooker, P.M, Lukins, H.B
• Format: Article
• Language: English
• Subjects: ADENOSINE TRIPHOSPHATE; ADENOSINTRIFOSFATO; AEP1; Amino Acid Sequence; ATP synthase; Base Sequence; Biological and medical sciences; Blotting, Northern; Cloning, Molecular; DNA, Fungal; DNA, Mitochondrial - genetics; EXPRESION GENICA; EXPRESSION DES GENES; Fundamental and applied biological sciences. Psychology; Fungal Proteins - genetics; Fungal Proteins - metabolism; GENE; Gene Expression Regulation, Fungal; GENES; Genes, Fungal; Genes, Regulator; Genes. Genome; Genetic Complementation Test; LIGASAS; LIGASE; Mitochondria; MITOCHONDRIE; MITOCONDRIA; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Mutation; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; PET gene; Phenotype; Proton-Translocating ATPases - biosynthesis; Proton-Translocating ATPases - genetics; Restriction Mapping; SACCHAROMYCES CEREVISIAE; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae Proteins; Transcription, Genetic; Yeast
• ISSN: 0172-8083; 1432-0983
• DOI: 10.1007/BF00324676

Due to mutation in a single nuclear locus, AEP1, the temperature-conditional pet mutant ts1860 of Saccharomyces cerevisiae fails to synthesize mitochondrial ATP synthase subunit 9 at the restrictive temperature of 36 degrees C. The presence at this temperature of near-normal levels of the cognate oli1 mRNA in mutant ts1860 indicates that, the product of the AEP1 gene is required for translation of the mitochondrial oli1 transcript. In this study the AEP1 gene has been cloned from a wild-type yeast genomic library by genetic complementation of a temperature-conditional aep1 strain at the restrictive temperature. A 2330-bp genomic fragment which restores subunit 9 synthesis in aep1 mutant strains was characterized. This fragment encoded five open reading frames: the longest of these, at 1,554 nucleotides, was identified as the AEPI gene, since disruption of this reading frame generated a non-conditional pet strain unable to synthesize subunit 9. The predicted product of AEP1 is a basic, hydrophilic protein of 59571 Da which possesses a putative mitochondrial address sequence. Hybridization studies with AEP1-specific probes indicate that the gene is located on chromosome 13 and produces several poly(A)(+) transcripts ranging in size from 0.9 to 2.7 kb. None of the identified reading frames share significant homologies with entries of several data bases.