title: Arrestin times for compartmentalised cAMP signalling and phosphodiesterase-4 enzymes.
abstract: Various methods reveal that cyclic AMP (cAMP) signalling in cells is compartmentalised. These methods use FRET probes based upon either protein kinase A (PKA) or EPAC, cAMP-gated ion channels, or the selective activation of AKAP-anchored PKA isoforms. The basis of compartmentalisation involves point sources of cAMP generation within sub-domains of the plasma membrane coupled to degradation by spatially segregated, anchored forms of cAMP phosphodiesterases. cAMP-specific phosphodiesterase-4 (PDE4) isoforms play a central role in determining compartmentalisation, as exemplified in cardiac myocytes and T cells. The PKA phosphorylation status of the beta2-adrenoreceptor, and hence its ability to switch its signalling from G(s) to G(i) and thus to activate ERK, is regulated dynamically by the agonist-stimulated recruitment of PDE4 to the receptor in complex with beta-arrestin. The co-receptor CD28 enhances signalling through the T-cell receptor by recruiting a PDE4/beta-arrestin complex, which then attenuates PKA phosphorylation of Csk.
authors.affiliation: Molecular Pharmacology Group, Division of Biochemistry and Molecular Biology, Institute of Biomedical & Life Sciences, Wolfson Building, University Avenue, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK.
authors.forename: George S
authors.initials: GS
authors.lastname: Baillie
authors.forename: Miles D
authors.initials: MD
authors.lastname: Houslay
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism*; D000818:Animals; D019390:Arrestins / Q000378:metabolism*; D002451:Cell Compartmentation / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism*; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D006801:Humans; D046911:Macromolecular Substances / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D015290:Second Messenger Systems / Q000502:physiology*
chemical_list: D019390:Arrestins; D046911:Macromolecular Substances; D011956:Receptors, Cell Surface; D000242:Cyclic AMP; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4