TY  - JOUR
A1  - Agarwal, Shailesh R.
A1  - Yang, Pei-Chi
A1  - Rice, Monica
A1  - Singer, Cherie A.
A1  - Nikolaev, Viacheslav O.
A1  - Lohse, Martin J.
A1  - Clancy, Colleen E.
A1  - Harvey, Robert D.
T1  - Role of Membrane Microdomains in Compartmentation of cAMP Signaling
JF  - PLOS ONE
N2  - Spatially restricting cAMP production to discrete subcellular locations permits selective regulation of specific functional responses. But exactly where and how cAMP signaling is confined is not fully understood. Different receptors and adenylyl cyclase isoforms responsible for cAMP production are not uniformly distributed between lipid raft and non-lipid raft domains of the plasma membrane. We sought to determine the role that these membrane domains play in organizing cAMP responses in HEK293 cells. The freely diffusible FRET-based biosensor Epac2-camps was used to measure global cAMP responses, while versions of the probe targeted to lipid raft (Epac2-MyrPalm) and non-raft (Epac2-CAAX) domains were used to monitor local cAMP production near the plasma membrane. Disruption of lipid rafts by cholesterol depletion selectively altered cAMP responses produced by raft-associated receptors. The results indicate that receptors associated with lipid raft as well as non-lipid raft domains can contribute to global cAMP responses. In addition, basal cAMP activity was found to be significantly higher in non-raft domains. This was supported by the fact that pharmacologic inhibition of adenylyl cyclase activity reduced basal cAMP activity detected by Epac2-CAAX but not Epac2-MyrPalm or Epac2-camps. Responses detected by Epac2-CAAX were also more sensitive to direct stimulation of adenylyl cyclase activity, but less sensitive to inhibition of phosphodiesterase activity. Quantitative modeling was used to demonstrate that differences in adenylyl cyclase and phosphodiesterase activities are necessary but not sufficient to explain compartmentation of cAMP associated with different microdomains of the plasma membrane.
KW  - protein-coupled-receptors
KW  - adenylyl-cyclase isoforms
KW  - adult cardiac myocytes
KW  - plasma membrane
KW  - lipid rafts
KW  - cholesterol depletion
KW  - BETA(2)-adrenergic receptor
KW  - living vells
KW  - cyclic-AMP
KW  - domains
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-116673
SN  - 1932-6203
VL  - 9
IS  - 4
ER  -