Premium
Role of Gravin in Compartmentalization of cAMP Signaling
Author(s) -
Thompson Gonowolo Faith,
Grove Bryon
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.558.11
Subject(s) - forskolin , microbiology and biotechnology , cytosol , chemistry , rolipram , redistribution (election) , ibmx , protein kinase a , phosphodiesterase , biophysics , biology , biochemistry , kinase , receptor , enzyme , politics , political science , law
A‐kinase anchoring proteins (AKAPs) play a critical role in signaling by targeting cAMP dependent signaling complexes to specific cellular sites. Gravin, a multivalent AKAP that targets PKA and possibly PDE4 to the cell membrane, undergoes redistribution to the cytosol in response to elevated [Ca 2+ ] i suggesting it may play a role in cross‐talk between Ca 2+ and cAMP dependent pathways. We have shown previously that gravin redistribution alters PKA activity in cytosolic and membrane regions, but the effect of gravin redistribution on cAMP levels in these compartments is unknown. To begin assessing this, we used a FRET based cAMP biosensor (lck‐EPAC2‐camps) targeted to the membrane to determine the effect of gravin expression on cAMP levels. Treatment of cells expressing the biosensor and gravin with IBMX showed a greater increase in cAMP levels compared to cells lacking gravin. In addition, cells expressing gravin and the biosensor, showed a significantly higher increase in cAMP when treated with rolipram (PDE4)/forskolin compared to cilostamide (PDE3)/forskolin. These experiments indicate that gravin expression affects cAMP levels at the membrane following PDE inhibition and sets the stage for determining the role of gravin redistribution in regulating cytosolic and membrane cAMP levels. EPAC2‐camps was a gift from Drs. V. Nikolaev and M. Lohse. Supported by NIH grants 1P30GM103329 and 1S100D016250‐01.