Heat shock protein HSP60 can alleviate the phenotype of mitochondrial RNA-deficient temperature-sensitive mna2 pet mutants.
mna2, which belongs to the class I 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.
Sanyal
A
A
Department of Medicine, University of Chicago, IL 60637.
Harington
A
A
Herbert
C J
CJ
Groudinsky
O
O
Slonimski
P P
PP
Tung
B
B
Getz
G S
GS
D000409:Alanine / Q000235:genetics; D000483:Alleles; D001483:Base Sequence; D015152:Blotting, Northern; D018834:Chaperonin 60 / Q000235:genetics / Q000502:physiology*; D004252:DNA Mutational Analysis; D004271:DNA, Fungal / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000502:physiology; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D007532:Isoleucine / Q000235:genetics; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D010101:Oxygen Consumption; D017354:Point Mutation; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D012331:RNA, Fungal / Q000096:biosynthesis* / Q000235:genetics; D000077278:RNA, Mitochondrial; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology; D013696:Temperature; D014633:Valine / Q000235:genetics
D018834:Chaperonin 60; D004271:DNA, Fungal; D005656:Fungal Proteins; D012331:RNA, Fungal; D000077278:RNA, Mitochondrial; D007532:Isoleucine; D012313:RNA; D014633:Valine; D000409:Alanine