[D-Arg(1),D-Trp(5,7,9),Leu(11)]Substance P inhibits bombesin-induced mitogenic signal transduction mediated by both G(q) and G(12) in Swiss 3T3cells.
Substance P (SP) analogues including [d-Arg(1),d-Trp(5,7,9), Leu(11)]SP are broad spectrum neuropeptide antagonists and potential anticancer agents, but their mechanism of action is not fully understood. Here, we examined the mechanism of action of [d-Arg(1), d-Trp(5,7,9),Leu(11)]SP as an inhibitor of G protein-coupled receptor (GPCR)-mediated signal transduction and cellular DNA synthesis in Swiss 3T3 cells. Addition of [d-Arg(1),d-Trp(5,7,9), Leu(11)]SP, at 10 micrometer, caused a striking rightward shift in the dose-response curves of DNA synthesis induced by bombesin, bradykinin, or vasopressin and markedly inhibited the activation of p42(mapk) (ERK-2) and p44(mapk) (ERK-1) induced by these GPCR agonists. In addition, this SP analogue also prevented the protein kinase C-dependent activation of protein kinase D induced by these agonists. [d-Arg(1),d-Trp(5,7,9),Leu(11)]SP, at a concentration (10 micrometer) that inhibited these G(q)-mediated events, also prevented GPCR agonist-induced responses mediated through the G proteins of the G(12) subfamily. These include bombesin-induced assembly of focal adhesions, formation of parallel arrays of actin stress fibers, increase in the tyrosine phosphorylation of focal adhesion kinase (FAK), p130(Cas), and paxillin, and formation of a complex between FAK and Src. We conclude that [d-Arg(1),d-Trp(5,7,9),Leu(11)]SP acts as a mitogenic antagonist of neuropeptide GPCRs blocking signal transduction via both G(q) and G(12).
Sinnett-Smith
J
J
Department of Medicine, School of Medicine and Molecular Biology Institute, UCLA, Los Angeles, California 90095-1786, USA.
Santiskulvong
C
C
Duque
J
J
Rozengurt
E
E
D016475:3T3 Cells; D000818:Animals; D001839:Bombesin / Q000037:antagonists & inhibitors*; D002448:Cell Adhesion / Q000187:drug effects; D050719:Crk-Associated Substrate Protein; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D044365:GTP-Binding Protein alpha Subunits, G12-G13; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D019204:GTP-Binding Proteins / Q000378:metabolism*; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008934:Mitogens / Q000037:antagonists & inhibitors*; D009479:Neuropeptides / Q000037:antagonists & inhibitors; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011493:Protein Kinase C / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011506:Proteins; D018004:Receptors, Bombesin / Q000378:metabolism; D050717:Retinoblastoma-Like Protein p130; D015398:Signal Transduction / Q000187:drug effects; D013373:Substance P / Q000031:analogs & derivatives* / Q000494:pharmacology
C493842:Bcar1 protein, mouse; D050719:Crk-Associated Substrate Protein; D003598:Cytoskeletal Proteins; D008934:Mitogens; D009479:Neuropeptides; D051419:Paxillin; D010750:Phosphoproteins; D011506:Proteins; C496062:Pxn protein, mouse; D018004:Receptors, Bombesin; D050717:Retinoblastoma-Like Protein p130; C102471:substance P, Arg(1)-Trp(5,7,9)-Leu(11)-; D013373:Substance P; D004247:DNA; C089212:protein kinase D; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496051:Ptk2 protein, mouse; D011493:Protein Kinase C; D020928:Mitogen-Activated Protein Kinases; D019204:GTP-Binding Proteins; D044365:GTP-Binding Protein alpha Subunits, G12-G13; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D020962:Heterotrimeric GTP-Binding Proteins; D001839:Bombesin