Disruption of the cyclic AMP phosphodiesterase-4 (PDE4)–HSP20 complex attenuates the β-agonist induced hypertrophic response in cardiac myocytes

Sin, Y.Y., Edwards, H.V., Li, X., Day, J.P., Christian, F. , Dunlop, A.J., Adams, D.R., Zaccolo, M., Houslay, M.D. and Baillie, G.S. (2011) Disruption of the cyclic AMP phosphodiesterase-4 (PDE4)–HSP20 complex attenuates the β-agonist induced hypertrophic response in cardiac myocytes. Journal of Molecular and Cellular Cardiology, 50(5), pp. 872-883. (doi: 10.1016/j.yjmcc.2011.02.006) (PMID:21334344)

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Abstract

The small heat shock protein HSP20 is known to be cardioprotective during times of stress and the mechanism underlying its protective abilities depends on its phosphorylation on Ser16 by PKA (protein kinase A). Although the external stimuli that trigger Ser16 phosphorylation have been well studied, the events that modulate spatial and temporal control of this modification remain to be clarified. Here, we report that inhibition of cAMP phosphodiesterase-4 (PDE4) induces the phosphorylation of HSP20 in resting cardiac myocytes and augments its phosphorylation by PKA following beta-adrenergic stimulation. Moreover, using peptide array technology, in vitro binding studies, co-immunoprecipitation techniques and immunocytochemistry, we show that HSP20 binds directly to PDE4 within a region of the conserved catalytic domain. We also show that FRET-based, genetically-encoded CAMP reporters anchored to HSP20 exhibit a larger response to PDE4 inhibition compared to free cytosolic cAMP reporters, suggesting that the interaction with PDE4 is crucial in modulating the highly localised pool of cAMP to which HSP20 is exposed. Using information gleaned from peptide array analyses, we developed a cell-permeable peptide that serves to inhibit the interaction of PDE4 with HSP20. Disruption of the HSP20-PDE4 complex, using this peptide, suffices to induce phosphorylation of HSP20 by PKA and to protect against the hypertrophic response measured in neonatal cardiac myocytes following chronic beta-adrenergic stimulation.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Baillie, Professor George and Houslay, Professor Miles and Zaccolo, Professor Manuela and Christian, Dr Frank and Sin, Dr Angie and Day, Dr Jonathan and Dunlop, Dr Allan
Authors: Sin, Y.Y., Edwards, H.V., Li, X., Day, J.P., Christian, F., Dunlop, A.J., Adams, D.R., Zaccolo, M., Houslay, M.D., and Baillie, G.S.
College/School:College of Medical Veterinary and Life Sciences > School of Molecular Biosciences
College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health
Journal Name:Journal of Molecular and Cellular Cardiology
Publisher:Elsevier
ISSN:0022-2828
ISSN (Online):1095-8584
Published Online:18 February 2011

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
438301Phosphodiesterase-4 isoforms - intracellular targeting, regulation and potential therapeutic targetsMiles HouslayMedical Research Council (MRC)G0600765Institute of Neuroscience and Psychology
432501Transatlantic networks of excellence in cardiovascular diseaseMiles HouslayFoundation Leducq (LEDUCQ-VIL)06 CVD 02Institute of Neuroscience and Psychology