CSD2, CSD3, and CSD4, genes required for chitin synthesis in Saccharomyces cerevisiae: the CSD2 gene product is related to chitin synthases and to developmentally regulated proteins in Rhizobium species and Xenopus laevis
| Autor: | C E Bulawa |
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| Rok vydání: | 1992 |
| Předmět: | |
| Zdroj: | Molecular and Cellular Biology. 12:1764-1776 |
| ISSN: | 1098-5549 0270-7306 |
| DOI: | 10.1128/mcb.12.4.1764 |
| Popis: | In Saccharomyces cerevisiae, chitin forms the primary division septum and the bud scar in the walls of vegetative cells. Three chitin synthetic activities have been detected. Two of them, chitin synthase I and chitin synthase II, are not required for synthesis of most of the chitin present in vivo. Using a novel screen, I have identified three mutations, designated csd2, csd3, and csd4, that reduce levels of chitin in vivo by as much as 10-fold without causing any obvious perturbation of cell division. The csd2 and csd4 mutants lack chitin synthase III activity in vitro, while csd3 mutants have wild-type levels of this enzyme. In certain genetic backgrounds, these mutations cause temperature-sensitive growth on rich medium; inclusion of salts or sorbitol bypasses this phenotype. Gene disruption experiments show that CSD2 is nonessential; a small amount of chitin, about 5% of the wild-type level, is detected in the disruptants. DNA sequencing indicates that the CSD2 protein has limited, but statistically significant, similarity to chitin synthase I and chitin synthase II. Other significant similarities are to two developmental proteins: the nodC protein from Rhizobium species and the DG42 protein of Xenopus laevis. The relationship between the nodC and CSD2 proteins suggests that nodC may encode an N-acetylglucosaminyltransferase that synthesizes the oligosaccharide backbone of the nodulation factor NodRm-1. |
| Databáze: | OpenAIRE |
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