Kinome analysis of rapid effects of DEX in activated CD4⁺T cells. (A) Peptide micro arrays (PepChip) incubated with lysates of activated CD4⁺ T cells treated with or without DEX. (B) Dot plot representing the phosphorylation status of specific peptide substrates spotted on the PepChip array. Differential kinase activities in lysates from activated cells incubated in the presence or absence of DEX using median densities of the spots are shown. Each spot represents the amount of phosphorylation of a specific peptide substrate. Lck/Fyn kinase consensus substrates demonstrated significantly decreased phosphorylation (0.32- and 0.51-fold changes) because of DEX. A full description of the substrates with significantly altered phosphorylation upon DEX treatment is provided in Figure S1. (C) The same data set was analyzed using a ranking method; each spot representing the phosphorylation status of a specific kinase pseudo-substrate. Because of the ranking method, a bisymmetric distribution is generated of peptides of which phosphorylation was either significantly increased or decreased because of DEX treatment. Peptide substrates demonstrating increased phosphorylation (corresponding with higher ranks of peptides) are reflected by an equivalent number of peptides of which phosphorylation was decreased because of DEX (lower ranks of peptides). Lck/Fyn kinase consensus substrates are marked by an arrow. Spots representing peptides of which phosphorylation is significant decreased (A), increased (C), or unaltered (B) as a result of DEX treatment are shown. DEX indicates dexamethasone.