Isolation of aSchizosaccharomyces pombe Gene Which in High Copy Confers Resistance to the Nucleoside Analogue 5-Azacytidine

Abstract

Treatment of Schizosaccharomyces pombe with the C5 DNA methyltransferase (C5Mtase) inhibitor 5‐azacytidine (5‐azaC) has previously been shown to induce G2 checkpoint‐dependent cell cycle arrest. S. pombe strains defective in both the checkpoint control pathways and in DNA repair processes are sensitive to 5‐azaC. Here we describe the isolation of azr1as a multi‐copy suppressor of the 5‐azaC sensitivity of G2 checkpoint and DNA repair‐deficient strains. azr1+ encodes a putative 25 kDa protein with limited homology to a Saccharomyces cerevisiae open reading frame of unknown function. The azr1+ gene is not essential and the null mutant shows no alteration in either DNA repair or checkpoint properties. We also report the sequence of the putative fission yeast cytidine deaminase gene, designated pcd1+, which lies immediately adjacent to azr1+ but which plays only a moderate role in suppression of 5‐azaC sensitivity. These data have been deposited with EMBL nucleotide sequence database, Accession Number X98329. © 1997 John Wiley & Sons, Ltd.

A novel type 2C protein phosphatase from the human fungal pathogen Candida albicans

“…: CAB07860), the At5g66720 gene product of Arabidopsis thaliana (GenBank accession No. : NP_201473) and the azr1 protein of Schizosaccharomyces pombe [5], respectively. The gene azr1 + was originally isolated as a multi‐copy suppressor of the 5‐azacytidine sensitivity of G2 checkpoint and DNA repair‐deficient S. pombe strains, but the nature of the azr1 protein was unknown [5].…”

“…: NP_201473) and the azr1 protein of Schizosaccharomyces pombe [5], respectively. The gene azr1 + was originally isolated as a multi‐copy suppressor of the 5‐azacytidine sensitivity of G2 checkpoint and DNA repair‐deficient S. pombe strains, but the nature of the azr1 protein was unknown [5]. We observed a potential PP2C catalytic domain in each of these proteins from the four eukaryotic model organisms (data not shown), indicating that the CaPTC7 phosphatase is highly conserved in eukaryotes.…”