Affiliations: Department of Applied Bioscience and Biotechnology,
Faculty of Life and Environmental Science, Shimane University, Matsue,
690-8504, Japan
Note: [] Address for correspondence: M. Kawamukai, Department of Applied
Bioscience and Biotechnology, Faculty of Life and Environmental Science,
Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Japan. Tel.: +81 852 32
6587; Fax: +81 852 32 6092; E-mail: [email protected]
Abstract: We have constructed coenzyme Q deficient fission yeast strains by
deletion of ten different genes, all of which are absolutely required for the
CoQ_{10} biosynthesis. We found that sulfide was highly
accumulated in all fission yeast CoQ_{10} deficient mutants.
In fission yeast sulfide is required for the synthesis of cysteine and
homocysteine which are catalyzed by cysteine synthase (Cys1a) and homocysteine
synthase (Met17), respectively. To better understand the relation between
sulfide metabolism and coenzyme Q, we expressed cys1a, met17 and
hmt2, which encodes sulfide-quinone oxidoreductase, in
CoQ_{10} deficient mutants and other mutants, and measured
the level of sulfide. Although expression of cys1a and met17
lowered sulfide production in CoQ_{10} deficient mutants,
hmt2 did not lower the level of sulfide, because Hmt2 requires coenzyme Q
for its function. In contrast, expression of hmt2 lowered sulfide
production in cys1a and met17 mutants. These and other results
indicate that coenzyme Q is important for sulfide oxidation through
sulfide-quinone oxidoreductase to detoxify excess sulfide in fission yeast.
