Panther Protein Class analysis (Table S4) identified Cytoskeletal Proteins, Transcription Factors, and Transferases as the three Protein Classes enriched in genes exhibiting a sustained response (Clusters i, ii, and v; P < 0.0001). Sustained up-regulation of G-protein modulators and guanyl-nucleotide exchange factors (Cluster i) was also observed. Several Protein Classes involved in interactions with Ca2+ (calcium-binding proteins, calmodulin and intracellular calcium-sensing proteins) were enriched only in Cluster v (sustained down-regulation). GPCRs, ligand-gated ion channels, membrane trafficking proteins and neuropeptides were also enriched in Cluster v.
