+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Long range control circuits within mitochondria and between nucleus and mitochondria 2. genetic and biochemical analyses of suppressors which selectively alleviate the mitochondrial intron mutations

Long range control circuits within mitochondria and between nucleus and mitochondria 2. genetic and biochemical analyses of suppressors which selectively alleviate the mitochondrial intron mutations

Molecular and General Genetics 184(3): 493-503

Two dominant nuclear (NAM1-1 and NAM2-1) and 1 mitochondrial (mim2-1) suppressors [in Saccharomyces cerevisiae] were studied. The action spectrum of these suppressors on 433 mit- mutations located in various mitochondrial genes were analyzed; they preferentially alleviate the effects of mutations located within intron open reading frames of the cob-box gene. These suppressors permit the maturation of cytochrome b mRNA by restoring the synthesis of intron encoded protein(s) catalytically involved in splicing, i.e., mRNA-maturase(s) (cf. Lazowska et al. 1980). NAM1-1 is allele specific and gene non-specific: it suppresses mutations located within different introns. NAM2-1 and mim2-1 are intron-specific: they suppress mutations all located in the same (box7) intron of the cob-box gene. Analyses of cytochrome absorption spectra and mitochondrial translation products of cells in which the suppressors are associated with various other mit- mutations show that the suppressors restore cytochrome b and/or cytochrome oxidase (cox I) synthesis, as expected from their growth phenotype. This suppression is, however, only partial: some new polypeptides characteristic of the mit- mutations can be still detected in the presence of suppressor. Interestingly enough when box7 specific suppressors NAM2-1 and mim2-1 are associated with a complete cob-box deletion (leading to a total deficiency of cytochrome b and oxidase) partial restoration of cox I synthesis is observed while cytochrome b is still totally absent. In strains carrying NAM2-1 or mim2-1 the presence of cytochrome b gene is no longer required for the expression of the oxi3 gene pointing out to the possibility of mutational switch-on of silent genes, whether mitochondrial, mim2-1, or nuclear, NAM2-1. This switch-on would permit the synthesis of an active maturase acting as a substitute for the box7 maturase in order to splice the cytochrome b and oxidase mRNA.

Please choose payment method:

(PDF emailed within 1 workday: $29.90)

Accession: 005827361

Download citation: RISBibTeXText

PMID: 7038398

Related references

Long range base pairing in the leftward transcription unit of bacteriophage lambda characterization by electron microscopy and computer aided sequence analysis. Journal of Molecular Biology 179(3): 351-366, 1984

Long range base pairing in bacteriophage X174 single-stranded DNA. Journal of Molecular Biology 142(2): 131-144, 1980

Long lasting energetic particle injection from a weak flare. Advances in Space Research 1(3): 69-72, 1981

Mitochondrial and nuclear glutamate dehydrogenases ec in chinese hamster ovary cells in culture. Biochimica et Biophysica Acta 429: 694-704, 1976

Long range effect of manures and fertilizers on soil physical properties and yield of sugarcane. Journal of the Indian Society of Soil Science 33(3): 704-706, 1985

Nuclear and mitochondrial deoxyribonucleic acid replication during mitosis in Saccharomyces cerevisiae. Journal of Bacteriology 123(2): 497-504, 1975

Quantitative bioanalysis of enantiomeric drugs using capillary electrophoresis and electrospray mass spectrometry. Journal of Pharmaceutical and Biomedical Analysis 31(5): 893-904, 1 April, 2003

Biogenesis of mitchondria. Phospholipid synthesis in vitro by yeast mitochondrial and microsomal fractions. Biochemical Journal 144(2): 265-275, 1974

Nuclear and mitochondrial dna synthesis in regeneration following acute tubular necrosis of the kidney. American Journal of Pathology 66(3): 62A, 1972

Very preterm children who do not cooperate with assessments at three years of age: skill differences at five years. Journal of Developmental and Behavioral Pediatrics 21(2): 107-113, 2000

Very rare cancers--a problem neglected. Lancet. Oncology 2(4): 189-189, 2002

RNA splicing at human immunodeficiency virus type 1 3' splice site A2 is regulated by binding of hnRNP A/B proteins to an exonic splicing silencer element. Journal of Virology 75(18): 8487-8497, 2001

RNA silencing in plants--defense and counterdefense. Science 2, 292(5525): 2277-2280, 2001

Biogenesis of mitochondria. XLI. Physical mapping of mitochondrial genetic markers in yeast. Journal of Molecular Biology 104(2): 485-503, 1976

Mitochondrial and nuclear mitoribosomal suppressors that enable misreading of ochre codons in yeast mitochondria : I. Isolation, localization and allelism of suppressors. Current Genetics 9(1): 1-10, 1984