Abstract
Although numerous receptors stimulate cAMP production in a wide array of cells, many elicit distinct, highly localized responses, implying that the subcellular distribution of cAMP is not uniform. One often used explanation is that phosphodiesterases, which breakdown cAMP, act as functional barriers limiting diffusion. However, several studies refute the notion that this is sufficient, suggesting that phosphodiesterase-independent movement of cAMP must occur at rates slower than free diffusion. But, until now this has never been demonstrated. Using Raster Image Correlation Spectroscopy (RICS), we measured the diffusion coefficient of a fluorescently-labeled cAMP derivative (φ450-cAMP) as well as other fluorescent molecules in order to investigate the role that molecular size, cell morphology, and buffering by protein kinase A (PKA) play in restricting cAMP mobility in different cell types. Our results demonstrate that cytosolic movement of cAMP is indeed much slower than the rate of free diffusion and that interactions with PKA, especially type II PKA associated with mitochondria, play a significant role. These findings have important implications with respect to cAMP signaling in all cells.
| Original language | English (US) |
|---|---|
| Article number | 19577 |
| Journal | Scientific Reports |
| Volume | 6 |
| DOIs | |
| State | Published - Jan 22 2016 |
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ASJC Scopus subject areas
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Cite this
Mechanisms Restricting Diffusion of Intracellular cAMP. / Agarwal, Shailesh R.; Clancy, Colleen E; Harvey, Robert D.
In: Scientific Reports, Vol. 6, 19577, 22.01.2016.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Mechanisms Restricting Diffusion of Intracellular cAMP
AU - Agarwal, Shailesh R.
AU - Clancy, Colleen E
AU - Harvey, Robert D.
PY - 2016/1/22
Y1 - 2016/1/22
N2 - Although numerous receptors stimulate cAMP production in a wide array of cells, many elicit distinct, highly localized responses, implying that the subcellular distribution of cAMP is not uniform. One often used explanation is that phosphodiesterases, which breakdown cAMP, act as functional barriers limiting diffusion. However, several studies refute the notion that this is sufficient, suggesting that phosphodiesterase-independent movement of cAMP must occur at rates slower than free diffusion. But, until now this has never been demonstrated. Using Raster Image Correlation Spectroscopy (RICS), we measured the diffusion coefficient of a fluorescently-labeled cAMP derivative (φ450-cAMP) as well as other fluorescent molecules in order to investigate the role that molecular size, cell morphology, and buffering by protein kinase A (PKA) play in restricting cAMP mobility in different cell types. Our results demonstrate that cytosolic movement of cAMP is indeed much slower than the rate of free diffusion and that interactions with PKA, especially type II PKA associated with mitochondria, play a significant role. These findings have important implications with respect to cAMP signaling in all cells.
AB - Although numerous receptors stimulate cAMP production in a wide array of cells, many elicit distinct, highly localized responses, implying that the subcellular distribution of cAMP is not uniform. One often used explanation is that phosphodiesterases, which breakdown cAMP, act as functional barriers limiting diffusion. However, several studies refute the notion that this is sufficient, suggesting that phosphodiesterase-independent movement of cAMP must occur at rates slower than free diffusion. But, until now this has never been demonstrated. Using Raster Image Correlation Spectroscopy (RICS), we measured the diffusion coefficient of a fluorescently-labeled cAMP derivative (φ450-cAMP) as well as other fluorescent molecules in order to investigate the role that molecular size, cell morphology, and buffering by protein kinase A (PKA) play in restricting cAMP mobility in different cell types. Our results demonstrate that cytosolic movement of cAMP is indeed much slower than the rate of free diffusion and that interactions with PKA, especially type II PKA associated with mitochondria, play a significant role. These findings have important implications with respect to cAMP signaling in all cells.
UR - http://www.scopus.com/inward/record.url?scp=84955498554&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84955498554&partnerID=8YFLogxK
U2 - 10.1038/srep19577
DO - 10.1038/srep19577
M3 - Article
C2 - 26795432
AN - SCOPUS:84955498554
VL - 6
JO - Scientific Reports
JF - Scientific Reports
SN - 2045-2322
M1 - 19577
ER -