Cloning and characterization of KNR4, a yeast gene involved in (1,3)-beta-glucan synthesis.

AUTOR(ES)

Hong, Z

RESUMO

k9 killer toxin from Hansenula mrakii was used to select a number of resistant mutants from Saccharomyces cerevisiae. Preliminary biochemical and genetic studies showed that some of them acquired structural defects in the cell wall. One of these mutants, the knr4-1 mutant, displays a number of cell wall defects, including osmotic sensitivity; sensitivity to cercosporamide, a known antifungal agent; and resistance to Zymolyase, a (1,3)-beta-glucanase. We report here the isolation and analysis of the KNR4 gene. DNA sequence analysis revealed an uninterrupted open reading frame which contains five potential start codons. The longest coding template encodes a protein of 505 amino acids with a calculated molecular mass of 57,044 Da. A data base search revealed 100% identity with a nuclear protein, SMI1p. Disruption of the KNR4 locus does not result in cell death; however, it leads to reduced levels of both (1,3)-beta-glucan synthase activity and (1,3)-beta-glucan content in the cell wall. The gene was mapped to the right arm of chromosome VII.

Documentos Relacionados

• Cloning and characterization of GNS1: a Saccharomyces cerevisiae gene involved in synthesis of 1,3-beta-glucan in vitro.
• Isolation of a gene involved in 1,3-beta-glucan synthesis in Aspergillus nidulans and purification of the corresponding protein.
• Cloning and characterization of a Neurospora crassa gene required for (1,3) beta-glucan synthase activity and cell wall formation.
• Cloning of the RHO1 gene from Candida albicans and its regulation of beta-1,3-glucan synthesis.
• [beta]-Glucan Synthesis in the Cotton Fiber (I. Identification of [beta]-1,4- and [beta]-1,3-Glucans Synthesized in Vitro).