Figure 1. Effect of genetic deletion of Tsc2 on signal transduction in mouse embryonic fibroblasts (MEFs) as determined by the phosphorylation of peptide arrays containing 1024 kinase substrates.

Graphical impression of the results obtained, representing three technical replicas performed on two biological replicates. Individual results for each technical replicate were first subjected to Markov state analysis. (i.e. is the peptide significantly more phosphorylated than the background?) and the number of reactions in which this is the case (an integer between zero [in none of the 6 reactions was significant radioactivity incorporated into the substrate peptide] and six [in all 6 reactions significant radioactivity was incorporated into the substrate peptide]) were determined per peptide for each of the experimental conditions (listed as Markov score, Supplementary Table 1). The Markov scores obtained were collapsed on signal categories that provide insight into the signaling differences between the Tsc2 proficient and deficient cells and are expressed in grey scale (representing the number of peptides phosphorylated as a fraction of all peptides in that category). Note the difference in mTOR signaling, PAK signaling and Chk1/2-related signaling.