Phosphodiesterase 4 interacts with the 5-HT4(b) receptor to regulate cAMP signaling

S Weninger; K Van Craenenbroeck; R T Cameron; F Vandeput; M A Movsesian; G S Baillie; R A Lefebvre

doi:10.1016/j.cellsig.2014.07.027

Phosphodiesterase 4 interacts with the 5-HT4(b) receptor to regulate cAMP signaling

Cell Signal. 2014 Nov;26(11):2573-82. doi: 10.1016/j.cellsig.2014.07.027. Epub 2014 Aug 4.

Authors

S Weninger¹, K Van Craenenbroeck², R T Cameron³, F Vandeput⁴, M A Movsesian⁴, G S Baillie³, R A Lefebvre⁵

Affiliations

¹ Heymans Institute of Pharmacology, Ghent University, De Pintelaan 185, Ghent 9000, Belgium.
² Laboratory for Eukaryotic Gene Expression and Signal Transduction, Ghent University, Proeftuinstraat 86, Ghent 9000, Belgium.
³ Institute of Cardiovascular and Medical Science, University of Glasgow, Office 534, Wolfson-Link Building, Glasgow G12 8QQ, UK.
⁴ Cardiovascular Medicine Division, VA Salt Lake City Health Care System and University of Utah School of Medicine, Salt Lake City, UT 84148, USA.
⁵ Heymans Institute of Pharmacology, Ghent University, De Pintelaan 185, Ghent 9000, Belgium. Electronic address: romain.lefebvre@ugent.be.

PMID: 25101859
DOI: 10.1016/j.cellsig.2014.07.027

Abstract

Phosphodiesterase (PDE) 3 and PDE4, which degrade cyclic adenosine monophosphate (cAMP), are important regulators of 5-hydroxytryptamine (5-HT) 4 receptor signaling in cardiac tissue. Therefore, we investigated whether they interact with the 5-HT4(b) receptor, and whether A-kinase anchoring proteins (AKAPs), scaffolding proteins that bind to the regulatory subunit of protein kinase A (PKA) and contribute to the spacial-temporal control of cAMP signaling, are involved in the regulation of 5-HT4(b) receptor signaling. By measuring PKA activity in the absence and presence of PDE3 and PDE4 inhibitiors, we found that constitutive signaling of the overexpressed HA-tagged 5-HT4(b) receptor in HEK293 cells is regulated predominantly by PDE4, with a secondary role for PDE3 that is unmasked in the presence of PDE4 inhibition. Overexpressed PDE4D3 and PDE3A1, and to a smaller extent PDE4D5 co-immunoprecipitate constitutively with the 5-HT4(b) receptor. PDE activity measurements in immunoprecipitates of the 5-HT4(b) receptor confirm the association of PDE4D3 with the receptor and provide evidence that the activity of this PDE may be increased upon receptor stimulation with 5-HT. A possible involvement of AKAPs in 5-HT4(b) receptor signaling was uncovered in experiments using the St-Ht31 inhibitor peptide, which disrupts the interaction of AKAPs with PKA. However, St-Ht31 did not influence 5-HT4(b) receptor-stimulated PKA activity, and endogenous AKAP79 and gravin were not found in immunoprecipitates of the 5-HT4(b) receptor. In conclusion, we found that both PDE3A1 and PDE4D3 are integrated into complexes that contain the 5-HT4(b) receptor and may thereby regulate 5-HT4(b) receptor-mediated signaling.

Keywords: 5-HT(4) receptor signaling; PDE3A1; PDE3A2; PDE3B; PDE4D3; PDE4D5.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

A Kinase Anchor Proteins / genetics
A Kinase Anchor Proteins / metabolism
Cyclic AMP / genetics
Cyclic AMP / metabolism*
Cyclic AMP-Dependent Protein Kinases / genetics
Cyclic AMP-Dependent Protein Kinases / metabolism
Cyclic Nucleotide Phosphodiesterases, Type 3 / genetics
Cyclic Nucleotide Phosphodiesterases, Type 3 / metabolism
Cyclic Nucleotide Phosphodiesterases, Type 4 / genetics
Cyclic Nucleotide Phosphodiesterases, Type 4 / metabolism*
HEK293 Cells
Humans
Receptors, Serotonin, 5-HT4 / genetics
Receptors, Serotonin, 5-HT4 / metabolism*
Second Messenger Systems / physiology*

Substances

A Kinase Anchor Proteins
AKAP5 protein, human
Receptors, Serotonin, 5-HT4
Cyclic AMP
Cyclic AMP-Dependent Protein Kinases
Cyclic Nucleotide Phosphodiesterases, Type 3
Cyclic Nucleotide Phosphodiesterases, Type 4
PDE3A protein, human

Grants and funding

G0600765/MRC_/Medical Research Council/United Kingdom