Involvement of Arp2/3 complex in MCP-1-induced chemotaxis.
The migrating monocyte shows dynamic actin polymerization in response to MCP-1. We investigated the involvement of the actin-related protein 2 and 3 complex (Arp2/3 complex) during chemotaxis of a human monocyte cell line (THP-1). To clarify whether the Arp2/3 complex directly polymerizes actin in response to MCP-1 stimulation, THP-1 cells were transfected with complementary DNA constructs encoding ScarWA. In ScarWA-transfected cells, neither recruitment of Arp2/3 complex at the leading edge nor actin polymerization was detected. Indeed, migration induced by MCP-1 was almost completely blocked. At the same time, transfection also interfered with the recruitment of integrin beta-1 at the leading edge and reduced affinity binding to fibronectin. Immunoprecipitation with an anti-Arp2 antibody showed that integrin beta-1 and WASP were co-precipitated under the condition of MCP-1 stimulation. These results indicate that interaction between the Arp2/3 complex and WASP stimulates actin polymerization and integrin beta-1-mediated adhesion during MCP-1-induced chemotaxis of THP-1 cells.
Mukai
Yasuo
Y
Department of Diagnostic Pathology, Tokyo Medical University, Tokyo, Japan.
Iwaya
Keiichi
K
Ogawa
Hitoshi
H
Mukai
Kiyoshi
K
D051377:Actin-Related Protein 2; D051378:Actin-Related Protein 3; D002460:Cell Line; D018932:Chemokine CCL2 / Q000494:pharmacology*; D002633:Chemotaxis / Q000187:drug effects / Q000502:physiology*; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D006801:Humans; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology
C495926:ACTR2 protein, human; C495928:ACTR3 protein, human; D051377:Actin-Related Protein 2; D051378:Actin-Related Protein 3; C111835:CCL2 protein, human; D018932:Chemokine CCL2; D003598:Cytoskeletal Proteins