Cyclooxygenase and cAMP-dependent protein kinase reorganize the actin cytoskeleton for motility in HeLa cells.
The adhesion of a cell to its surrounding matrix is a key determinant in many aspects of cell behavior. Adhesion consists of distinct stages : attachment, cell spreading, motility, and/or immobilization. Interrelated signaling pathways regulate these stages, and many adhesion-related signals control the architecture of the cytoskeleton. The various cytoskeletal organizations then give rise to the specific stages of adhesion. It has been shown that arachidonic acid acts at a signaling branch point during cell attachment. Arachidonic acid is metabolized via lipoxygenase to activate actin polymerization and cell spreading. It is also metabolized by cyclooxygenase to generate small actin bundles. We have used confocal microscopy and indirect immunofluorescence to investigate the structure of these cyclooxygenase dependent actin bundles in HeLa cells. We have also employed cell migration assays and pharmacological modulation of cyclooxygenase and downstream signals. The results indicate that cyclooxygenase and PKA stimulate the formation of actin bundles that contain myosin II and associate with small focal adhesions. In addition, we demonstrate that this cytoskeletal organization correlates with increased cell motility.
Glenn
Honor L
HL
Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003l, USA. jacobson@biochem.umass.edu
Jacobson
Bruce S
BS
D000199:Actins / Q000187:drug effects* / Q000648:ultrastructure*; D000818:Animals; D002465:Cell Movement; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases / Q000502:physiology*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D003599:Cytoskeleton / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology; D019084:Fluorescent Antibody Technique, Indirect; D022001:Focal Adhesions; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D018613:Microscopy, Confocal; D024462:Myosin Type II / Q000378:metabolism; D041681:NIH 3T3 Cells; D011451:Prostaglandin-Endoperoxide Synthases / Q000502:physiology*; D022502:Stress Fibers / Q000378:metabolism
D000199:Actins; D016861:Cyclooxygenase Inhibitors; D011451:Prostaglandin-Endoperoxide Synthases; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases; D024462:Myosin Type II