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Title: Principal role of adenylyl cyclase 6 in K⁺ channel regulation and vasodilator signalling in vascular smooth muscle cells.
Authors: Nelson, Carl P.
Rainbow, Richard D.
Brignell, Jennifer L.
Perry, Matthew D.
Willets, Jonathon M.
Davies, Noel W.
Standen, Nicholas B.
Challiss, R.A. John
First Published: 1-Sep-2011
Publisher: Oxford University Press (OUP) for European Society of Cardiology
Citation: Cardiovascular Research, 2011, 91 (4), pp. 694-702
Abstract: AIMS: Membrane potential is a key determinant of vascular tone and many vasodilators act through the modulation of ion channel currents [e.g. the ATP-sensitive potassium channel (K(ATP))] involved in setting the membrane potential. Adenylyl cyclase (AC) isoenzymes are potentially important intermediaries in such vasodilator signalling pathways. Vascular smooth muscle cells (VSMCs) express multiple AC isoenzymes, but the reason for such redundancy is unknown. We investigated which of these isoenzymes are involved in vasodilator signalling and regulation of vascular ion channels important in modulating membrane potential. METHODS AND RESULTS: AC isoenzymes were selectively depleted (by >75%) by transfection of cultured VSMCs with selective short interfering RNA sequences. AC6 was the predominant isoenzyme involved in vasodilator-mediated cAMP accumulation in VSMCs, accounting for ∼60% of the total response to β-adrenoceptor (β-AR) stimulation. AC3 played a minor role in β-AR signalling, whereas AC5 made no significant contribution. AC6 was also the principal isoenzyme involved in β-AR-mediated protein kinase A (PKA) signalling (determined using the fluorescent biosensor for PKA activity, AKAR3) and the substantial β-AR/PKA-dependent enhancement of K(ATP) current. K(ATP) current was shown to play a vital role in setting the resting membrane potential and in mediating the hyperpolarization observed upon β-AR stimulation. CONCLUSION: AC6, but not the closely related AC5, plays a principal role in vasodilator signalling and regulation of the membrane potential in VSMCs. These findings identify AC6 as a vital component in the vasodilatory apparatus central to the control of blood pressure.
DOI Link: 10.1093/cvr/cvr137
ISSN: 0008-6363
eISSN: 1755-3245
Type: Journal Article
Rights: Published on behalf of the European Society of Cardiology. All rights reserved. Copyright The Author 2011. For permissions please email: The online version of this article has been published under an open access model. Users are entitled to use, reproduce, disseminate, or display the open access version of this article for noncommercial purposes provided that the original authorship is properly and fully attributed; the Journal, Learned Society and Oxford University Press are attributed as the original place of publication with correct citation details given; if an article is subsequently reproduced or disseminated not in its entirety but only in part or as a derivative work this must be clearly indicated.
Appears in Collections:Published Articles, Dept. of Cardiovascular Sciences

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