TY - JOUR
T1 - Role of clathrin-mediated endocytosis in CXCR2 sequestration, resensitization, and signal transduction
AU - Yang, Wei
AU - Wang, Dingzhi
AU - Richmond, Ann
PY - 1999/4/16
Y1 - 1999/4/16
N2 - CXCR2 is a seven-transmembrane receptor that transduces intracellular signals in response to the chemokines interleukin-8, melanoma growth- stimulatory activity/growth-regulatory protein, and other ELR motif- containing CXC chemokines by coupling to heterotrimeric GTP-binding proteins. In this study, we explored the mechanism responsible for ligand-induced CXCR2 endocytosis. Here, we demonstrate that dynamin, a component of clathrin- mediated endocytosis, is essential for CXCR2 endocytosis and resensitization. In HEK293 cells, dynamin I K44A, a dominant-negative mutant of dynamin that inhibits the clathrin-mediated endocytosis, blocks the ligand-stimulated CXCR2 sequestration. Furthermore, co-expression of dynamin I K44A significantly delays dephosphorylation of CXCR2 after ligand stimulation, suggesting that clathrin-mediated endocytosis plays an important role in receptor dephosphorylation and resensitization. In addition, ligand-mediated receptor down-regulation is attenuated when receptor internalization is inhibited by dynamin I K44A. Interestingly, inhibition of receptor endocytosis by dynamin I K44A does not affect the CXCR2-mediated stimulation of mitogen-activated protein kinase. Most significantly, our data indicate that the ligand-stimulated receptor endocytosis is required for CXCR2- mediated chemotaxis in HEK293 cells. Taken together, our findings suggest that clathrin-mediated CXCR2 internalization is crucial for receptor endocytosis, resensitization, and chemotaxis.
AB - CXCR2 is a seven-transmembrane receptor that transduces intracellular signals in response to the chemokines interleukin-8, melanoma growth- stimulatory activity/growth-regulatory protein, and other ELR motif- containing CXC chemokines by coupling to heterotrimeric GTP-binding proteins. In this study, we explored the mechanism responsible for ligand-induced CXCR2 endocytosis. Here, we demonstrate that dynamin, a component of clathrin- mediated endocytosis, is essential for CXCR2 endocytosis and resensitization. In HEK293 cells, dynamin I K44A, a dominant-negative mutant of dynamin that inhibits the clathrin-mediated endocytosis, blocks the ligand-stimulated CXCR2 sequestration. Furthermore, co-expression of dynamin I K44A significantly delays dephosphorylation of CXCR2 after ligand stimulation, suggesting that clathrin-mediated endocytosis plays an important role in receptor dephosphorylation and resensitization. In addition, ligand-mediated receptor down-regulation is attenuated when receptor internalization is inhibited by dynamin I K44A. Interestingly, inhibition of receptor endocytosis by dynamin I K44A does not affect the CXCR2-mediated stimulation of mitogen-activated protein kinase. Most significantly, our data indicate that the ligand-stimulated receptor endocytosis is required for CXCR2- mediated chemotaxis in HEK293 cells. Taken together, our findings suggest that clathrin-mediated CXCR2 internalization is crucial for receptor endocytosis, resensitization, and chemotaxis.
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U2 - 10.1074/jbc.274.16.11328
DO - 10.1074/jbc.274.16.11328
M3 - Article
C2 - 10196223
AN - SCOPUS:0033574539
SN - 0021-9258
VL - 274
SP - 11328
EP - 11333
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 16
ER -