title: PDE4-regulated cAMP degradation controls the assembly of integrin-dependent actin adhesion structures and REF52 cell migration.
abstract: Plating of REF52 cells onto extracellular matrix components leads to the formation of integrin-dependent actin adhesion microspikes. We show that the formation of these structures is sensitive to chemical agents that regulate cAMP levels, such as forskolin and IBMX. In particular, by using the specific inhibitor rolipram, we identify the PDE4 family of cAMP-specific phosphodiesterases as critical regulators of this process. The effect of PDE4 on microspike formation is mediated by actions exerted through the activation of PKA - rather than through the alternative cAMP effector, Epac. We provide evidence that peripheral microspikes are RhoA-, ROCK- and myosin-dependent, and that this pathway is suppressed by PDE4 inhibition. In addition, PDE4 inhibition impairs cell locomotion that requires dynamic protrusion and retraction of peripheral spike structures. Our data demonstrate that PDE4 activity is a key modulator of integrin-induced actin assembly at the cell periphery which, in turn, controls cell migration.
authors.affiliation: Institute of Biological and Life Sciences, Davidson and Wolfson Buildings, University of Glasgow, Glasgow G12 8QQ, UK. y.fleming@beatson.gla.ac.uk
authors.forename: Yvonne M
authors.initials: YM
authors.lastname: Fleming
authors.forename: Margaret C
authors.initials: MC
authors.lastname: Frame
authors.forename: Miles D
authors.initials: MD
authors.lastname: Houslay
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000199:Actins / Q000378:metabolism*; D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D004622:Embryo, Mammalian / Q000166:cytology; D004789:Enzyme Activation / Q000187:drug effects; D005347:Fibroblasts / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D016023:Integrins / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D007797:Laminin / Q000378:metabolism; D009219:Myosin-Light-Chain Kinase / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011554:Pseudopodia / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D020889:Rolipram / Q000494:pharmacology; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism; D020744:rac GTP-Binding Proteins / Q000378:metabolism; D020830:rac1 GTP-Binding Protein; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
chemical_list: D000199:Actins; D016023:Integrins; D047908:Intracellular Signaling Peptides and Proteins; D007797:Laminin; D009479:Neuropeptides; C107953:RAC1 protein, human; D005576:Colforsin; D000242:Cyclic AMP; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D009219:Myosin-Light-Chain Kinase; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D020764:cdc42 GTP-Binding Protein; D020744:rac GTP-Binding Proteins; D020830:rac1 GTP-Binding Protein; D020742:rhoA GTP-Binding Protein; D020889:Rolipram; D015056:1-Methyl-3-isobutylxanthine