Inhibition of Glycolate and D-Lactate Metabolism in a Mutant of Chlamydomonas Reinhardtii Deficient in Mitochondrial Respiration

Husic, Diane W.; Tolbert, N. E.

doi:10.1007/978-94-017-0516-5_117

Cited by 7 publications

(10 citation statements)

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“…[23] suggested that in the presence of SHAM to inhibit cyanide-insensitive alternative pathway, mutants deficient in cyanide-sensitive respiration may be lethal because NADH produced in the Krebs cycle could not be oxidized. Husic and Tolbert [10] showed that in the presence of SHAM, the nuclear dk-97 mutant defective for cytochrome c oxidase accumulates tricarboxylic acid cycle intermediates during photosynthetic 14CO2 fixation. The glycolate produced during photosynthesis also accumulates in the mutant, which suggests that its oxidation can be mediated by the SHAM-sensitive pathway [ 10].…”

Section: Discussionmentioning

confidence: 99%

“…Husic and Tolbert [10] showed that in the presence of SHAM, the nuclear dk-97 mutant defective for cytochrome c oxidase accumulates tricarboxylic acid cycle intermediates during photosynthetic 14CO2 fixation. The glycolate produced during photosynthesis also accumulates in the mutant, which suggests that its oxidation can be mediated by the SHAM-sensitive pathway [ 10]. The importance of the alternative pathway is also demonstrated by the inhibitory effect of 0.3 mM SHAM on mixotrophic growth of the dum-3 mutant; the alternative pathway can also be essential when the cyanide-sensitive pathway is functional since in the wild-type strain, SHAM (0.3 mM) is inhibitory under heterotrophic growth and reduces growth under mixotrophic conditions (M.-P. Dorthu and R.F.…”

Section: Discussionmentioning

confidence: 99%

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Biochemical, genetic and molecular characterization of new respiratory-deficient mutants inChlamydomonas reinhardtii

et al. 1992

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Eight respiratory-deficient mutants of Chlamydomonas reinhardtii have been isolated after mutagenic treatment with acriflavine or ethidium bromide. They are characterized by their inability to grow or their very reduced growth under heterotrophic conditions. One mutation (Class III) is of nuclear origin whereas the seven remaining mutants (Classes I and II) display a predominantly paternal mt- inheritance, typical of mutations residing in the mitochondrial DNA. Biochemical analysis has shown that all mutants are deficient in the cyanide-sensitive cytochrome pathway of the respiration whereas the alternative pathway is still functional. Measurements of complexes II + III (antimycin-sensitive succinate-cytochrome c oxido-reductase) and complex IV (cytochrome c oxidase) activities allowed to conclude that six mutations have to be localized in the mitochondrial apocytochrome b (COB) gene, one in the mitochondrial cytochrome oxidase subunit I (COI) gene and one in a nuclear gene encoding a component of the cytochrome oxidase complex. By using specific probes, we have moreover demonstrated that five mutants (Class II mutants) contain mitochondrial DNA molecules deleted in the terminal end containing the COB gene and the telomeric region; they also possess dimeric molecules resulting from end-to-end junctions of deleted monomers. The two other mitochondrial mutants (Class I) have no detectable gross alteration. Class I and Class II mutants can also be distinguished by the pattern of transmission of the mutation in crosses. An in vivo staining test has been developed to identify rapidly the mutants impaired in cyanide-sensitive respiration.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Biochemical, genetic and molecular characterization of new respiratory-deficient mutants inChlamydomonas reinhardtii

et al. 1992

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“…The parental strains (CC-314, CC-1039) were obtained from the Chlamydomonas Genetics Center at Duke University (Durham, NC). Chlamydomonas CC-314 (dk97) has been reported to exhibit 3 to 11 % of wild-type Cyt oxidase activity (9,28).…”

Section: Materials and Methods Algal Strainsmentioning

confidence: 99%

Cytochrome and Alternative Pathway Respiration in Green Algae

Weger¹,

Guy²,

Turpin³

1990

Plant Physiol.

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Inhibitor titration curves and discrimination against 1802 by mitochondrial respiration in three strains of green algae (Selenastrum minutum [Naeg.] Collins, and two strains of Chlamydomonas reinhardtii Dangeard) with differing respiratory capabilities were determined. Discrimination for cytochrome pathway respiration ranged from 19.89 to 20.43%. Discrimination for altemative pathway respiration by wild-type C. reinhardtii (measured in the presence of KCN) was 25.46%, while discrimination values for a cytochrome oxidase deficient mutant of C. reinhardtii ranged from 24.24 to 24.96%. In the absence of KCN, the alternative pathway was not engaged in wild-type C. reinhardtii, the only algal strain that possessed both cytochrome and altemative pathway capacities.

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“…Aside from the classic cytochrome pathway of respiration (complexes III and IV), an alternative pathway insensitive to KCN but sensitive to salicylhydroxamic acid (SHAM) branches from the main chain at the level of the ubiquinone pool (Wiseman et al, 1977;Husic and Tolbert, 1987;Matagne et al, 1989). Because the alternative pathway is not associated with proton translocation, the oxidation of one NADH molecule via this route generates only one ATP molecule, whereas three ATP molecules are produced when oxidation occurs via the cytochrome pathway ( Figure 5).…”

Section: Respiratory Chain and Complex I Activitiesmentioning

confidence: 99%

Alteration of Dark Respiration and Reduction of Phototrophic Growth in a Mitochondrial DNA Deletion Mutant of Chlamydomonas Lacking cob, nd4, and the 3′ End of nd5

Duby

Matagne

1999

Plant Cell

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We describe here a new type of mitochondrial mutation ( dum24 ; for dark uniparental minus inheritance) of the unicellular photosynthetic alga Chlamydomonas reinhardtii . The mutant fails to grow under heterotrophic conditions and displays reduced growth under both photoautotrophic and mixotrophic conditions. In reciprocal crosses between mutant and wild-type cells, the meiotic progeny only inherit the phenotype of the mating-type minus parent, indicating that the dum24 mutation exclusively affects the mitochondrial genome. Digestion with various restriction enzymes followed by DNA gel blot hybridizations with specific probes demonstrated that dum24 cells contain four types of altered mitochondrial genomes: deleted monomers lacking cob , nd4 , and the 3 Ј end of the nd5 gene; deleted monomers deprived of cob , nd4 , nd5 , and the 5 Ј end of the cox1 coding sequence; and two types of dimers produced by end-to-end fusions between monomers similarly or differently deleted. Due to these mitochondrial DNA alterations, complex I activity, the cytochrome pathway of respiration, and presumably, the three phosphorylation sites associated with these enzyme activities are lacking in the mutant. The low respiratory rate of the dum24 cells results from the activities of rotenoneresistant NADH dehydrogenase, complex II, and alternative oxidase, with none of these enzymes being coupled to ATP production. To our knowledge, this type of mitochondrial mutation has never been described for photosynthetic organisms or more generally for obligate aerobes.

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Inhibition of Glycolate and D-Lactate Metabolism in a Mutant of Chlamydomonas Reinhardtii Deficient in Mitochondrial Respiration

Cited by 7 publications

References 8 publications

Biochemical, genetic and molecular characterization of new respiratory-deficient mutants inChlamydomonas reinhardtii

Biochemical, genetic and molecular characterization of new respiratory-deficient mutants inChlamydomonas reinhardtii

Cytochrome and Alternative Pathway Respiration in Green Algae

Alteration of Dark Respiration and Reduction of Phototrophic Growth in a Mitochondrial DNA Deletion Mutant of Chlamydomonas Lacking cob, nd4, and the 3′ End of nd5

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