Tyrosine phosphatase SHP-2 regulates IL-1 signaling in fibroblasts through focal adhesions.
Interleukin-1beta (IL-1beta) mediates destruction of matrix collagens in diverse inflammatory diseases including arthritis, periodontitis, and pulmonary fibrosis by activating fibroblasts, cells that interact with matrix proteins through integrin-based adhesions. In vitro, IL-1beta signaling is modulated by focal adhesions, supramolecular protein complexes that are enriched with tyrosine kinases and phosphatases. We assessed the importance of tyrosine phosphatases in regulating cell-matrix interactions and IL-1beta signaling. In human gingival fibroblasts plated on fibronectin, IL-1beta enhanced the maturation of focal adhesions as defined by morphology and enrichment with paxillin and alpha-actinin. IL-1beta also induced activation of ERK and recruitment of phospho-ERK to focal complexes/adhesions. Treatment with the potent tyrosine phosphatase inhibitor pervanadate, in the absence of IL-1beta, recapitulated many of these responses indicating the importance of tyrosine phosphatases. Immunoblotting of collagen bead-associated complexes revealed that the tyrosine phosphatase, SHP-2, was also enriched in focal complexes/adhesions. Depletion of SHP-2 by siRNA or by homologous recombination markedly altered IL-1beta-induced ERK activation and maturation of focal adhesions. IL-1beta-induced tyrosine phosphorylation of SHP-2 on residue Y542 promoted focal adhesion maturation. Association of Gab1 with SHP-2 in focal adhesions correlated temporally with activation of ERK and was abrogated in cells expressing mutant (Y542F) SHP-2. We conclude that IL-1beta mediated maturation of focal adhesions is dependent on tyrosine phosphorylation of SHP-2 at Y542, leading to recruitment of Gab1, a process that may influence the downstream activation of ERK.
Herrera Abreu
Maria Teresa
MT
Department of Medicine, University of Toronto, Toronto General Hospital Research Institute of the University Health Network, Ontario, Canada.
Wang
Qin
Q
Vachon
Eric
E
Suzuki
Tomoko
T
Chow
Chung-Wai
CW
Wang
Yingchun
Y
Hong
Ouyang
O
Villar
Jesús
J
McCulloch
Christopher A G
CA
Downey
Gregory P
GP
D000185:Actinin / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D003094:Collagen / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism*; D005353:Fibronectins / Q000494:pharmacology; D022001:Focal Adhesions / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D047908:Intracellular Signaling Peptides and Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D009154:Mutation; D051419:Paxillin / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D015398:Signal Transduction / Q000502:physiology*; D014162:Transfection; D014443:Tyrosine / Q000378:metabolism; D014638:Vanadates / Q000494:pharmacology
D048868:Adaptor Proteins, Signal Transducing; D004791:Enzyme Inhibitors; D005353:Fibronectins; C098587:GAB1 protein, human; D007375:Interleukin-1; D047908:Intracellular Signaling Peptides and Proteins; D051419:Paxillin; D034741:RNA, Small Interfering; C076715:pervanadate; D000185:Actinin; D014638:Vanadates; D014443:Tyrosine; D003094:Collagen; D048049:Extracellular Signal-Regulated MAP Kinases; C516724:PTPN11 protein, human; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D017027:Protein Tyrosine Phosphatases; C516725:Ptpn11 protein, mouse