Table I

Functionally related clusters of regulated transcripts identified both by TSAA and ICAT analysis a

GO categoriesNumber of genes detected byp values
Expression down-regulated to 0.75 or lower
    Carboxylic acid transport23428.9E-080.0001
    Vitamin/cofactor transport3220.0090.004
    Nuclear protein export12320.00020.009
    DNA replication fidelity9310.020.001
Expression up-regulated to 1.5 or higher
    Protein catabolism19840.0092.1E-06
    Response to pheromone22215.0E-070.07
  • a Those genes whose estimated rates of protein expression from TSAA (Fig. 4) were down-regulated to <0.75 or up-regulated to >1.5 by α-factor, relative to untreated cells, were analyzed (869 genes up and 1081 genes down) using the gene ontology (GO) tools available on the Saccharomyces Genome Database ( An identical analysis was carried out with the regulated proteins revealed through ICAT analysis (49 up- and 79 down-regulated). Those genes that were significantly over-represented in both the TSAA and ICAT datasets are given above, along with the probabilities that the observed frequencies could have occurred by chance.