Heat shock protein HSP60 can alleviate the phenotype of mitochondrial RNA-deficient temperature-sensitive mna2 pet mutants

• Published in: Molecular & general genetics Vol. 246; no. 1; p. 56
• Main Authors: Sanyal, A, Harington, A, Herbert, C.J, Groudinsky, O, Slonimski, P.P, Tung, B, Getz, G.S. (Chicago Univ., IL (USA). Dept. of Medicine)
• Format: Journal Article
• Language: English
• Published: Germany 01.01.1995
• Subjects: Alanine - genetics; Alleles; ARN; Base Sequence; Blotting, Northern; Chaperonin 60 - genetics; Chaperonin 60 - physiology; Conservative single amino acid substitutions; DNA Mutational Analysis; DNA, Fungal - metabolism; ESTRES TERMICO; Fungal Proteins - genetics; Fungal Proteins - physiology; Genes, Fungal; Genetic Complementation Test; Heat shock protein; Isoleucine - genetics; Mitochondria - genetics; Mitochondria - metabolism; Mitochondrial biogenesis; MITOCHONDRIE; MITOCONDRIA; Molecular Sequence Data; MUTANT; MUTANTES; Oxygen Consumption; Pflanzenzuechtung; Point Mutation; PROTEINAS; PROTEINE; RESISTANCE A LA TEMPERATURE; RESISTENCIA A LA TEMPERATURA; Restriction Mapping; RNA - biosynthesis; RNA - genetics; RNA, Fungal - biosynthesis; RNA, Fungal - genetics; RNA, Mitochondrial; SACCHAROMYCES CEREVISIAE; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - physiology; STRESS THERMIQUE; Temperature; Temperature-sensitive mutants; Valine - genetics
• ISSN: 0026-8925; 1432-1874
• DOI: 10.1007/BF00290133

mna2, which belongs to the class 1 temperature-sensitive pet mutants that lose mitochondrial (mt)RNA at restrictive temperature, was shown by complementation and sequence determination to correspond to the gene coding for HSP60. Both mna2-1 and mna2-2, the two available alleles of mna2, have conservative single amino acid substitutions in the HSP60 gene. Valine substitutes for an alanine (position 47) in mna2-1, and an isoleucine substitutes for a valine (position 77) in mna2-2. These substitutions result in defects in respiration and in steady-state mtRNA accumulation. Wild-type hsp60 alleviates the mtRNA phenotype completely, while partially relieving the respiratory deficiency.