Inhibition of geranylgeranylation blocks agonist-induced actin reorganization in human airway smooth muscle cells.
To determine whether RhoA isoprenylation (geranylgeranylation) is required for agonist-induced actin cytoskeleton reorganization (measured by an increase in the filamentous F- to monomeric G-actin ratio), human airway smooth muscle cells were treated for 72 h with inhibitors of geranylgeranyltransferase I. Geranylgeranyltransferase inhibitor (GGTI)-2147 or -286 pretreatment completely blocked the increase in the F- to G-actin fluorescence ratio when cells were stimulated with lysophosphatidic acid (LPA), endothelin, or carbachol. In contrast, LPA or endothelin induced actin cytoskeletal reorganization in cells treated with farnesyltransferase inhibitor (FTI)-277 to inactivate Ras. Forskolin-induced adenylyl cyclase activity was inhibited by carbachol in GGTI-2147-pretreated cells, demonstrating that the effect of geranylgeranyltransferase I inhibition on stress fiber formation was not due to uncoupling of signaling between the heterotrimeric G(i) protein (the Ggamma subunit is isoprenylated) and distal effectors. These results demonstrate that selective GGTIs can inhibit agonist-induced actin reorganization.
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Department of Anesthesiology, College of Physicians and Surgeons of Columbia University, New York, New York 10032, USA. RL344@columbia.edu
Emala
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Lee
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Zhu
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Panettieri
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Hirshman
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D000199:Actins / Q000378:metabolism*; D019883:Alkyl and Aryl Transferases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002217:Carbachol / Q000494:pharmacology; D002478:Cells, Cultured; D016232:Endothelins / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D051231:Farnesyltranstransferase; D006801:Humans; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D008246:Lysophospholipids / Q000494:pharmacology; D008715:Methionine / Q000031:analogs & derivatives / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D008916:Miotics / Q000494:pharmacology; D009130:Muscle, Smooth / Q000166:cytology / Q000378:metabolism*; D022502:Stress Fibers / Q000378:metabolism; D014132:Trachea / Q000166:cytology / Q000378:metabolism*; D018631:ras Proteins / Q000378:metabolism; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
D000199:Actins; D016232:Endothelins; D004791:Enzyme Inhibitors; C096856:FTI 277; C437105:GGTI 286; D008246:Lysophospholipids; D008916:Miotics; D002217:Carbachol; D008715:Methionine; D019883:Alkyl and Aryl Transferases; C083291:geranylgeranyltransferase type-I; D051231:Farnesyltranstransferase; D018631:ras Proteins; D020742:rhoA GTP-Binding Protein; D007930:Leucine