Post-translational modifications in 5 metabolic vs. 5 signaling pathways. (A) Predicted mucin-type O-glycosylation (O-GalNAc), (B) N-glycosylation and (C) SUMOylation (Small Ubiquitin-like Modifier) sites are more frequent in signaling (blue bars) vs. metabolic pathways (orange bars). (D)-(F) Predicted frequency of 212 kinase phosphorylation sites (normalized to number and length of proteins within a given pathway to enable comparison across groups). Panel D represents a hierarchical clustering using all 212 kinases (Euclidean distance); the predicted frequency of a given kinase phosphorylation site is color-coded with yellow and red representing low and high expression, respectively. Panel E highlights 21 kinases from Panel D. Only two kinase phosphorylation sites were found to be enriched in metabolic pathways (NEK2 and MAPK2K6). (F) Signaling pathways showed a statistically significant overrepresentation of serine/threonine phosphorylation sites, and to a lesser degree tyrosine phosphorylation sites compared to metabolic pathways (p < 0.01, Wilcoxon-test). For each KEGG pathway, boxplots delineate the median value as well as the 25th and 75th percentiles. The raw data, i.e. individual values for local FDR for the comparison of 5 metabolic vs. 5 signaling pathways are plotted as diamonds next to the boxplots.
Barth et al. BMC Genomics 2010 11:197 doi:10.1186/1471-2164-11-197