Phosphoproteome of Embryonic Stem Cells

2DGE two-dimensional gel electrophoresis ES embryonic stem ESC embryonic stem cell EB embryoid body pI isoelectric point MS/MS tandem mass spectrometry Summary Embryonic stem cells are a unique cell population, capable both of self-renewal and of differentiation into all tissues in the adult organism. Despite the central importance of these cells, little information is available regarding the intracellular signaling pathways that govern self-renewal or early steps in the differentiation program. ES cell growth and differentiation correlates with kinase activities but with the exception of the JAK/STAT3 pathway, the relevant substrates are unknown. To identify candidate phosphoproteins with potential relevance to ESC differentiation, a systems biology approach was used. Proteins were purified using phosphoprotein-affinity columns, then separated by two-dimensional gel electrophoresis and detected by silver stain, before being identified by tandem mas