Stn1, a new Saccharomyces cerevisiae protein, is implicated in telomere size regulation in association with Cdc13.
We have isolated STN1, an essential Saccharomyces cerevisiae gene, as a suppressor of the cdc13-1 mutation. A synthetic lethal interaction between a temperature-sensitive mutant allele of STN1, stn1-13, and cdc13-1 was observed. Stn1 and Cdc13 proteins displayed a physical interaction by two-hybrid analysis. As shown previously for cdc13-1, stn1-13 cells at the restrictive temperature accumulate single-stranded DNA in subtelomeric regions of the chromosomes, but to a lesser extent than cdc13-1 cells. In addition, both Cdc13 and Stn1 were found to be involved in the regulation of telomere length, mutations in STN1 or CDC13 conferring an increase in telomere size. Loss of Stn1 function activated the RAD9 and MEC3 G2/M checkpoints, therefore confirming that DNA damage is generated. We propose that Stn1 functions in telomere metabolism during late S phase in cooperation with Cdc13.
Grandin
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Yeast Cell Cycle Group, Unité Mixte de Recherche Centre National de laRecherche Scientifique/Ecole Normale Supérieure (UMR CNRS/ENS), no. 49, Lyon, France.
Reed
S I
SI
Charbonneau
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M
D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000378:metabolism; D019926:Cyclin B; D016213:Cyclins / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D015966:Gene Expression Regulation, Fungal; D005804:Genes, Lethal; D006358:Hot Temperature; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D016615:Telomere
D018797:Cell Cycle Proteins; D019926:Cyclin B; D016213:Cyclins; D005656:Fungal Proteins; C099938:MEC3 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C069930:rad9 protein