%0 Journal Article %1 Landa2005 %A Landa, Jr. %A Harbeck, M. %A Kaihara, K. %A Chepurny, O. %A Kitiphongspattana, K. %A Graf, O. %A Nikolaev, V. O. %A Lohse, M. J. %A Holz, G. G. %A Roe, M. W. %D 2005 %J J Biol Chem %K & *Islets AMP/analogs Agents/metabolism Animals Calcium/*metabolism Cell Chloride/metabolism Cyclic Dyes/metabolism Energy Exchange Factors/genetics/metabolism Fluorescence Fluorescent Fusion Glucose/metabolism Guanine Hypoglycemic Insulin/*metabolism Langerhans/cytology/metabolism Line Messenger Mice Nucleotide Potassium Proteins/genetics/metabolism Recombinant Resonance Second Systems/physiology Tetraethylammonium/metabolism Tolbutamide/metabolism Transfer derivatives/*metabolism of %N 35 %P 31294-302 %T Interplay of Ca2+ and cAMP signaling in the insulin-secreting MIN6 beta-cell line %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15987680 %V 280 %X Ca2+ and cAMP are important second messengers that regulate multiple cellular processes. Although previous studies have suggested direct interactions between Ca2+ and cAMP signaling pathways, the underlying mechanisms remain unresolved. In particular, direct evidence for Ca2+-regulated cAMP production in living cells is incomplete. Genetically encoded fluorescence resonance energy transfer-based biosensors have made possible real-time imaging of spatial and temporal gradients of intracellular cAMP concentration in single living cells. Here, we used confocal microscopy, fluorescence resonance energy transfer, and insulin-secreting MIN6 cells expressing Epac1-camps, a biosynthetic unimolecular cAMP indicator, to better understand the role of intracellular Ca2+ in cAMP production. We report that depolarization with high external K+, tolbutamide, or glucose caused a rapid increase in cAMP that was dependent on extracellular Ca2+ and inhibited by nitrendipine, a Ca2+ channel blocker, or 2',5'-dideoxyadenosine, a P-site antagonist of transmembrane adenylate cyclases. Stimulation of MIN6 cells with glucose in the presence of tetraethylammonium chloride generated concomitant Ca2+ and cAMP oscillations that were abolished in the absence of extracellular Ca2+ and blocked by 2',5'-dideoxyadenosine or 3-isobutyl-1-methylxanthine, an inhibitor of phosphodiesterase. Simultaneous measurements of Ca2+ and cAMP concentrations with Fura-2 and Epac1-camps, respectively, revealed a close temporal and causal interrelationship between the increases in cytoplasmic Ca2+ and cAMP levels following membrane depolarization. These findings indicate highly coordinated interplay between Ca2+ and cAMP signaling in electrically excitable endocrine cells and suggest that Ca2+-dependent cAMP oscillations are derived from an increase in adenylate cyclase activity and periodic activation and inactivation of cAMP-hydrolyzing phosphodiesterase.

@article{Landa2005, abstract = {Ca2+ and cAMP are important second messengers that regulate multiple cellular processes. Although previous studies have suggested direct interactions between Ca2+ and cAMP signaling pathways, the underlying mechanisms remain unresolved. In particular, direct evidence for Ca2+-regulated cAMP production in living cells is incomplete. Genetically encoded fluorescence resonance energy transfer-based biosensors have made possible real-time imaging of spatial and temporal gradients of intracellular cAMP concentration in single living cells. Here, we used confocal microscopy, fluorescence resonance energy transfer, and insulin-secreting MIN6 cells expressing Epac1-camps, a biosynthetic unimolecular cAMP indicator, to better understand the role of intracellular Ca2+ in cAMP production. We report that depolarization with high external K+, tolbutamide, or glucose caused a rapid increase in cAMP that was dependent on extracellular Ca2+ and inhibited by nitrendipine, a Ca2+ channel blocker, or 2',5'-dideoxyadenosine, a P-site antagonist of transmembrane adenylate cyclases. Stimulation of MIN6 cells with glucose in the presence of tetraethylammonium chloride generated concomitant Ca2+ and cAMP oscillations that were abolished in the absence of extracellular Ca2+ and blocked by 2',5'-dideoxyadenosine or 3-isobutyl-1-methylxanthine, an inhibitor of phosphodiesterase. Simultaneous measurements of Ca2+ and cAMP concentrations with Fura-2 and Epac1-camps, respectively, revealed a close temporal and causal interrelationship between the increases in cytoplasmic Ca2+ and cAMP levels following membrane depolarization. These findings indicate highly coordinated interplay between Ca2+ and cAMP signaling in electrically excitable endocrine cells and suggest that Ca2+-dependent cAMP oscillations are derived from an increase in adenylate cyclase activity and periodic activation and inactivation of cAMP-hydrolyzing phosphodiesterase.}, added-at = {2010-12-14T18:12:02.000+0100}, author = {Landa, Jr. and Harbeck, M. and Kaihara, K. and Chepurny, O. and Kitiphongspattana, K. and Graf, O. and Nikolaev, V. O. and Lohse, M. J. and Holz, G. G. and Roe, M. W.}, biburl = {https://www.bibsonomy.org/bibtex/2d19d1042b5f12a66edf3c1c0a00323f6/pharmawuerz}, endnotereftype = {Journal Article}, interhash = {ba763c1055fb6b261e72a35dad37d59b}, intrahash = {d19d1042b5f12a66edf3c1c0a00323f6}, issn = {0021-9258 (Print) 0021-9258 (Linking)}, journal = {J Biol Chem}, keywords = {& *Islets AMP/analogs Agents/metabolism Animals Calcium/*metabolism Cell Chloride/metabolism Cyclic Dyes/metabolism Energy Exchange Factors/genetics/metabolism Fluorescence Fluorescent Fusion Glucose/metabolism Guanine Hypoglycemic Insulin/*metabolism Langerhans/cytology/metabolism Line Messenger Mice Nucleotide Potassium Proteins/genetics/metabolism Recombinant Resonance Second Systems/physiology Tetraethylammonium/metabolism Tolbutamide/metabolism Transfer derivatives/*metabolism of}, month = {Sep 2}, note = {Landa, Luis R Jr Harbeck, Mark Kaihara, Kelly Chepurny, Oleg Kitiphongspattana, Kajorn Graf, Oliver Nikolaev, Viacheslav O Lohse, Martin J Holz, George G Roe, Michael W DK45817/DK/NIDDK NIH HHS/United States DK63493/DK/NIDDK NIH HHS/United States DK64162/DK/NIDDK NIH HHS/United States DK68822/DK/NIDDK NIH HHS/United States Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S. United States The Journal of biological chemistry J Biol Chem. 2005 Sep 2;280(35):31294-302. Epub 2005 Jun 29.}, number = 35, pages = {31294-302}, shorttitle = {Interplay of Ca2+ and cAMP signaling in the insulin-secreting MIN6 beta-cell line}, timestamp = {2010-12-14T18:12:19.000+0100}, title = {Interplay of Ca2+ and cAMP signaling in the insulin-secreting MIN6 beta-cell line}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15987680}, volume = 280, year = 2005 }