![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
Vol. 55, Issue 6, 1020-1027, June 1999
Parke-Davis Neuroscience Research Centre, Cambridge University
Forvie Site, Cambridge, United Kingdom
Although activation of G protein-coupled inward rectifying
K+ (GIRK) channels by Gi/Go-coupled
receptors has been shown to be important in postsynaptic inhibition in
the central nervous system, there is also evidence to suggest that
inhibition of GIRK channels by Gq-coupled receptors is
involved in postsynaptic excitation. In the present study we addressed
whether the Gq-coupled receptors of the bombesin family can
couple to GIRK channels and examined the mechanism by which this
process occurs. Different combinations of GIRK channel subunits
(Kir3.1, Kir3.2, and Kir3.4) and bombesin receptors (BB1
and BB2) were expressed in Xenopus oocytes.
In all combinations tested GIRK currents were reversibly inhibited upon
application of the bombesin-related peptides, neuromedin B or
gastrin-releasing peptide in a concentration-dependent manner. Incubation of oocytes in the phospholipase C inhibitor U73122 or the
protein kinase C (PKC) inhibitors chelerythrine and staurosporine significantly reduced the inhibition of GIRK currents by neuromedin B,
whereas the Ca2+ chelator, BAPTA-AM had no effect. The
involvement of PKC was further demonstrated by direct inhibition of
GIRK currents by the phorbol esters, phorbol-12,13-dibutyrate and
phorbol-12-myristate-13-acetate. In contrast, the inactive phorbol
ester 4
-phorbol and protein kinase A activators, forskolin and
8-bromo cAMP did not inhibit GIRK currents. At the single-channel
level, direct activation of PKC using phorbol ester
phorbol-12,13-dibutyrate caused a dramatic reduction in open
probability of GIRK channels due to an increase in duration of the
interburst interval.
This article has been cited by other articles:
|
|
 |
|
  J.-W. Sohn, A. Lim, S.-H. Lee, and W.-K. Ho Decrease in PIP2 channel interactions is the final common mechanism involved in PKC- and arachidonic acid-mediated inhibitions of GABAB-activated K+ current J. Physiol., August 1, 2007; 582(3): 1037 - 1046. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y.-H. Yeh, J. R. Ehrlich, X. Qi, T. E. Hebert, D. Chartier, and S. Nattel Adrenergic control of a constitutively active acetylcholine-regulated potassium current in canine atrial cardiomyocytes Cardiovasc Res, June 1, 2007; 74(3): 406 - 415. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. F. Perez, F. J. White, and X.-T. Hu Dopamine D2 Receptor Modulation of K+ Channel Activity Regulates Excitability of Nucleus Accumbens Neurons at Different Membrane Potentials J Neurophysiol, November 1, 2006; 96(5): 2217 - 2228. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. G. Brown, A. Thomas, L. V. Dekker, A. Tinker, and J. L. Leaney PKC-{delta} sensitizes Kir3.1/3.2 channels to changes in membrane phospholipid levels after M3 receptor activation in HEK-293 cells Am J Physiol Cell Physiol, September 1, 2005; 289(3): C543 - C556. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 X. Du, H. Zhang, C. Lopes, T. Mirshahi, T. Rohacs, and D. E. Logothetis Characteristic Interactions with Phosphatidylinositol 4,5-Bisphosphate Determine Regulation of Kir Channels by Diverse Modulators J. Biol. Chem., September 3, 2004; 279(36): 37271 - 37281. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. K. Filippov, J. M. Fernandez-Fernandez, S. J. Marsh, J. Simon, E. A. Barnard, and D. A. Brown Activation and Inhibition of Neuronal G Protein-Gated Inwardly Rectifying K+ Channels by P2Y Nucleotide Receptors Mol. Pharmacol., September 1, 2004; 66(3): 468 - 477. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Zhang, J.-K. Lee, S. A. John, N. Uozumi, and I. Kodama Mechanosensitivity of GIRK Channels Is Mediated by Protein Kinase C-dependent Channel-Phosphatidylinositol 4,5-Bisphosphate Interaction J. Biol. Chem., February 20, 2004; 279(8): 7037 - 7047. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Mao, X. Wang, F. Chen, R. Wang, A. Rojas, Y. Shi, H. Piao, and C. Jiang Molecular basis for the inhibition of G protein-coupled inward rectifier K+ channels by protein kinase C PNAS, January 27, 2004; 101(4): 1087 - 1092. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Mao, L. Li, M. McManus, J. Wu, N. Cui, and C. Jiang Molecular Determinants for Activation of G-protein-coupled Inward Rectifier K+ (GIRK) Channels by Extracellular Acidosis J. Biol. Chem., November 22, 2002; 277(48): 46166 - 46171. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Bunemann, T. Meyer, L. Pott, and M. Hosey Novel Inhibition of Gbeta gamma -activated Potassium Currents Induced by M2 Muscarinic Receptors via a Pertussis Toxin-insensitive Pathway J. Biol. Chem., April 21, 2000; 275(17): 12537 - 12545. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. J. Hill and E. G. Peralta Inhibition of a Gi-activated Potassium Channel (GIRK1/4) by the Gq-coupled m1 Muscarinic Acetylcholine Receptor J. Biol. Chem., February 16, 2001; 276(8): 5505 - 5510. [Abstract] [Full Text] [PDF]
|
|
 |
 |
 |
|
 |
 |
 |
