title: Time-resolved dissection of early phosphoproteome and ensuing proteome changes in response to TGF-β.
abstract: Transforming growth factor-β (TGF-β) signaling promotes cell motility by inducing epithelial-to-mesenchymal transitions (EMTs) in normal physiology and development, as well as in pathological conditions, such as cancer. We performed a time-resolved analysis of the proteomic and phosphoproteomic changes of cultured human keratinocytes undergoing EMT and cell cycle arrest in response to stimulation with TGF-β. We quantified significant changes in 2079 proteins and 2892 phosphorylation sites regulated by TGF-β. We identified several proteins known to be involved in TGF-β-induced cellular processes, such as the cytostatic response, extracellular matrix remodeling, and epithelial dedifferentiation. In addition, we identified proteins involved in other cellular functions, such as vesicle trafficking, that were not previously associated with TGF-β signaling. Although many TGF-β responses are mediated by phosphorylation of the transcriptional regulators of the SMAD family by the TGF-β receptor complex, we observed rapid kinetics of changes in protein phosphorylation, indicating that many responses were mediated through SMAD-independent TGF-β signaling. Combined analysis of changes in protein abundance and phosphorylation and knowledge of protein interactions and transcriptional regulation provided a comprehensive representation of the dynamic signaling events underlying TGF-β-induced changes in cell behavior. Our data suggest that in epithelial cells stimulated with TGF-β, early signaling is a mixture of both pro- and antiproliferative signals, whereas later signaling primarily inhibits proliferation.
authors: Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany.
authors: Rochelle C J
authors: RC
authors: D'Souza
authors: Department of Molecular Cell Biology, Cancer Genomics Centre Netherlands, Leiden University Medical Center, Postbus 9600, 2300 RC Leiden, the Netherlands. Department of Medical Biochemistry and Genetics, and Turku Doctoral Program of Biomedical Sciences, University of Turku, FI-20520 Turku, Finland.
authors: Anna M
authors: AM
authors: Knittle
authors: Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany.
authors: Nagarjuna
authors: N
authors: Nagaraj
authors: Department of Molecular Cell Biology, Cancer Genomics Centre Netherlands, Leiden University Medical Center, Postbus 9600, 2300 RC Leiden, the Netherlands.
authors: Maarten
authors: M
authors: van Dinther
authors: Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany. Novo Nordisk Foundation Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3b, 2200 Copenhagen, Denmark.
authors: Chunaram
authors: C
authors: Choudhary
authors: Department of Molecular Cell Biology, Cancer Genomics Centre Netherlands, Leiden University Medical Center, Postbus 9600, 2300 RC Leiden, the Netherlands.
authors: Peter
authors: P
authors: ten Dijke
authors: Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany. Novo Nordisk Foundation Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3b, 2200 Copenhagen, Denmark.
authors: Matthias
authors: M
authors: Mann
authors: Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany. kisharma@biochem.mpg.de.
authors: Kirti
authors: K
authors: Sharma
mesh_terms: D059447:Cell Cycle Checkpoints / Q000187:drug effects; D002460:Cell Line; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D020543:Proteome / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
chemical_list: D010750:Phosphoproteins; D020543:Proteome; D016212:Transforming Growth Factor beta