Monocyte chemoattractant protein 1 causes differential signalling mediated by proline-rich tyrosine kinase 2 in THP-1 cells.
Monocyte chemoattractant protein 1 (MCP-1) has a crucial role in atherogenesis and inflammation. However, MCP-1-mediated signalling pathways in monocytes have not been fully elucidated. In the present study we investigated the role of tyrosine kinases such as proline-rich tyrosine kinase 2 (Pyk2) in MCP-1-mediated signal transduction in the monocytic cell line THP-1. Pyk2 was tyrosine phosphorylated very quickly after stimulation with MCP-1. We found that Lyn, Shc and paxillin were also tyrosine phosphorylated by MCP-1. We examined the association of these molecules by immunoprecipitation and immunoblot analysis. The association of Pyk2 with Lyn was dependent on stimulation with MCP-1 and on tyrosine phosphorylation of Pyk2. Phosphorylation of p38 was also dependent on tyrosine phosphorylation of Pyk2. However, the association of Pyk2 with paxillin and Grb2 was not affected by stimulation with MCP-1. Phosphorylation of ERK (extracellular-signal-regulated protein kinase) was not affected by overexpression of kinase-negative Pyk2. Our results indicate that Pyk2 forms a complex with paxillin, Grb2 and Lyn in THP-1 cells. However, Pyk2 is not always involved in MCP-1-mediated signalling pathways.
Yamasaki
M
M
Department of Geriatric Medicine, Kyoto University Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan.
Arai
H
H
Ashida
N
N
Ishii
K
K
Kita
T
T
D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D018932:Chemokine CCL2 / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004789:Enzyme Activation; D051418:Focal Adhesion Kinase 2; D051380:GRB2 Adaptor Protein; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D055765:Shc Signaling Adaptor Proteins; D015398:Signal Transduction / Q000502:physiology*; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000378:metabolism; D019061:src-Family Kinases / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D018932:Chemokine CCL2; D003598:Cytoskeletal Proteins; D051380:GRB2 Adaptor Protein; C495948:GRB2 protein, human; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; D011506:Proteins; C528024:SHC1 protein, human; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D051418:Focal Adhesion Kinase 2; C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases; D020928:Mitogen-Activated Protein Kinases