Table I

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

GO categoriesNumber of genes detected byp values
TSAAICATBothTSAAICAT
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 (www.yeastgenome.org). 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.