Yeast W303 yox1yhp1 mutant cell cycle

Two homeodomain proteins, Yox1 and Yhp1, act as repressors at early cell cycle boxes (ECBs) to restrict their activity to the M/G1 phase of the cell cycle in budding yeast. These proteins bind to Mcm1 and to a typical homeodomain binding site. The expression of Yox1 is periodic and directly correlated with its binding to, and repression of, ECB activity. The absence of Yox1 and Yhp1 or the constitutive expression of Yox1 leads to the loss of cell-cycle regulation of ECB activity. Therefore, the cell-cycle-regulated expression of these repressors defines the interval of ECB-dependent transcription. Twenty-eight genes, including MCM2-7, CDC6, SWI4, CLN3, and a number of genes required during late M phase have been identified that are coordinately regulated by this pathway. Keywords: cell cycle time course Cells were synchronized with alpha factor and sampled every 10 min across 2 cell cycles. A total of 13 samples were analyzed. No replicates were included. cDNA of the cell cycle samples were labelled with Cy5. For Cy3 labelling, asynchronous yeast population was used.