Control of DNA synthesis genes in fission yeast by the cell-cycle gene <i>cdc10</i>⁺

Abstract

In the budding yeast Saccharomyces cerevisiae, cell-cycle control over DNA synthesis occurs partly through the coordinate expression in late G1 phase of many, if not all, of the genes required for DNA synthesis. A cis-acting hexamer element ACGCGT (an MluI restriction site) is responsible for coordinating transcriptional regulation of these genes at the G1/S phase boundary and we have identified a binding activity, DSC1, that recognizes these sequences in a cell-cycle-dependent manner. In the distantly related fission yeast Schizosaccharomyces pombe, only one of the known DNA synthesis genes, &lt;i&gt;cdc22&lt;/i&gt;&lt;sup&gt;+&lt;/sup&gt;, which encodes a subunit of ribonucleotide reductase, is periodically expressed in late G1 (ref. 6). The promoter region of &lt;i&gt;cdc22&lt;/i&gt;&lt;sup&gt;+&lt;/sup&gt; has two MluI sites and five related sequences, suggesting that similar controls over DNA synthesis genes could occur in fission yeast. We report here a binding activity in fission yeast that is very similar to DSC1 in budding yeast. We also show that the fission yeast &lt;i&gt;cdc10&lt;/i&gt;&lt;sup&gt;+&lt;/sup&gt; gene product, which is required for Start and entry into S phase, is a component of this binding activity