chs-4, a class IV chitin synthase gene fromNeurospora crassa
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InSaccharomyces cerevisiae, most of the cellular chitin is produced by chitin synthase III, which requires the product encoded by theCSD2/CAL1/DIT101/KT12 gene. We have identified, isolated and structurally characterized aCSD2/CAL1/DIT101/KT12 homologue in the filamentous ascomyceteNeurospora crassa and have used a “reverse genetics” approach to determine its role in vivo. The yeast gene was used as a heterologous probe for the isolation of aN. crassa gene (designatedchs-4) encoding a polypeptide belonging to a class of chitin synthases which we have designated class IV. The predicted polypeptide encoded by this gene is highly similar to those ofS. cerevisiae andCandida albicans. N. crassa strains in whichchs-4 had been inactivated by the Repeat-Induced Point mutation (RIP) process grew and developed in a normal manner under standard growth conditions. However, when grown in the presence of sorbose (a carbon source which induces morphological changes accompanied by elevated chitin content), chitin levels in thechs-4 RIP strain were significantly lower than those observed in the wild type. We suggest that CHS4 may serve as an auxiliary enzyme inN. crassa and that, in contrast to yeasts, it is possible that filamentous fungi may have more than one class IV chitin synthase.
Key wordsNeurospora Ascomycete Fungal cell wall
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- Burnett JH (1979) Aspects of the structure and growth of hyphal walls. In: Burnett JH, Trinci APJ (eds) Fungal walls and hyphal growth. Cambridge University Press, Cambridge, pp 1–25Google Scholar
- Davis RH, de Serres FJ (1970) Genetic and microbiological research techniques forNeurospora crassa. Methods Enzymol 17A:79–143Google Scholar
- Motoyama T, Sudoh M, Horiuchi H, Ohta A, Takagi M (1994a) Isolation and characterization of two chitin synthase gene ofRhizopus oligosporus. Biosci Biotech Biochem 58:1685–1693Google Scholar
- Motoyama T, Kojima N, Horiuchi H, Ohta A, Takagi M (1994b) Isolation of a chitin synthase gene (chsC) ofAspergillus nidulens. Biosci Biotech Biochem 58:2254–2257Google Scholar
- Sambrook J, Fritsch EF, Maniatis T (1989) Molecular cloning: a laboratory manual. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New YorkGoogle Scholar
- Staben C, Jensen B, Singer M, Pollock J, Schectman M, Kinsey J, Selker E (1989) Use of a bacterial hygromycin B resistance gene as a dominant selectable marker inNeurospora crassa transformation. Fungal Genet Newslett 36:79–81Google Scholar
- Vogel HJ (1956) A convenient growth medium forNeurospora crassa (medium N). Microbiol Genet Bull 13:42–43Google Scholar
- Yanai K, Kojima N, Takaya N, Horiuchi H, Ohta A, Takagi M (1994) Isolation and characterization of two chitin synthase genes fromAspergillus nidulans. Biosci Biotech Biochem 58:1828–1835Google Scholar