Phosphorylation dynamics during early differentiation of human embryonic stem cells.
Pluripotent stem cells self-renew indefinitely and possess characteristic protein-protein networks that remodel during differentiation. How this occurs is poorly understood. Using quantitative mass spectrometry, we analyzed the (phospho)proteome of human embryonic stem cells (hESCs) during differentiation induced by bone morphogenetic protein (BMP) and removal of hESC growth factors. Of 5222 proteins identified, 1399 were phosphorylated on 3067 residues. Approximately 50% of these phosphosites were regulated within 1 hr of differentiation induction, revealing a complex interplay of phosphorylation networks spanning different signaling pathways and kinase activities. Among the phosphorylated proteins was the pluripotency-associated protein SOX2, which was SUMOylated as a result of phosphorylation. Using the data to predict kinase-substrate relationships, we reconstructed the hESC kinome; CDK1/2 emerged as central in controlling self-renewal and lineage specification. The findings provide new insights into how hESCs exit the pluripotent state and present the hESC (phospho)proteome resource as a complement to existing pluripotency network databases.
Van Hoof
Dennis
D
Developmental Biology and Stem Cell Research, Hubrecht Institute, Utrecht, The Netherlands.
Muñoz
Javier
J
Braam
Stefan R
SR
Pinkse
Martijn W H
MW
Linding
Rune
R
Heck
Albert J R
AJ
Mummery
Christine L
CL
Krijgsveld
Jeroen
J
D019485:Bone Morphogenetic Proteins / Q000494:pharmacology; D016203:CDC2 Protein Kinase / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D051357:Cyclin-Dependent Kinase 2 / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000187:drug effects / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D010750:Phosphoproteins / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology; D039904:Pluripotent Stem Cells / Q000187:drug effects / Q000378:metabolism*; D020543:Proteome / Q000187:drug effects / Q000378:metabolism*; D055748:SOXB1 Transcription Factors / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology
D019485:Bone Morphogenetic Proteins; D010750:Phosphoproteins; D020543:Proteome; C527782:SOX2 protein, human; D055748:SOXB1 Transcription Factors; D016203:CDC2 Protein Kinase; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2