| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Articles in PresS, published online ahead of print May 16, 2002
Am J Physiol Heart Circ Physiol, 10.1152/ajpheart.00934.2001
Submitted on October 30, 2001
Accepted on May 8, 2002
1 Pathology, McGill University, Montreal, Quebec, Canada; Medicine, Research Center, Montreal Heart Institute, Montreal, Quebec, Canada
2 Medicine, Research Center, Montreal Heart Institute, Montreal, Quebec, Canada
3 Physiology, McGill University, Montreal, Quebec, Canada
4 Medicine, Research Center, Montreal Heart Institute, Montreal, Quebec, Canada; Medicine, University of Montreal, Montreal, Quebec, Canada; Pharmacology, McGill University, Montreal, Quebec, Canada
* To whom correspondence should be addressed. E-mail: nattel{at}icm.umontreal.ca.
Ventricular inward-rectifier current (IK1) is substantially larger than atrial, producing functionally important action potential differences. To evaluate possible molecular mechanisms, we recorded IK1 with patch-clamp and studied Kir2.1 and 2.3 subunit expression. IK1 density was >10-fold larger in canine ventricle than atrium. Kir2.1 protein expression (Western blot) was 78% greater(P < 0.01) in ventricle, but Kir2.3 band density was 228% greater (P < 0.01) in atrium. Immunocytochemistry showed transverse-tubular localization of Kir2.1 in 89% (17/19) of ventricular and 26% (5/19, P < 0.0001) of atrial cells. Both exhibited a weakly-positive Kir2.1 signal at the intercalated disks. Kir2.3 was strongly-expressed at the intercalated disks in all cells and in the transverse-tubular regions in 78% (14/18) of atrial and 22% (4/18, P < 0.001) of ventricular cells. Tissue immunohistochemical results qualitatively resembled isolated cell data. We conclude that the expression density and subcellular localization of Kir2.1 and 2.3 subunits differ in canine atrium versus ventricle. Overall protein density differences are insufficient to explain IK1 discrepancies, which may be related to differences in subcellular distribution.
This article has been cited by other articles:
|
|
 |
|
  D. Ponce-Balbuena, A. Lopez-Izquierdo, T. Ferrer, A. A. Rodriguez-Menchaca, I. A. Arechiga-Figueroa, and J. A. Sanchez-Chapula Tamoxifen Inhibits Inward Rectifier K+ 2.x Family of Inward Rectifier Channels by Interfering with Phosphatidylinositol 4,5-Bisphosphate-Channel Interactions J. Pharmacol. Exp. Ther., November 1, 2009; 331(2): 563 - 573. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. L. Vikstrom, R. Vaidyanathan, S. Levinsohn, R. P. O'Connell, Y. Qian, M. Crye, J. H. Mills, and J. M. B. Anumonwo SAP97 regulates Kir2.3 channels by multiple mechanisms Am J Physiol Heart Circ Physiol, October 1, 2009; 297(4): H1387 - H1397. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Philip-Couderc, N. I. Tavares, A. Roatti, R. Lerch, C. Montessuit, and A. J. Baertschi Forkhead Transcription Factors Coordinate Expression of Myocardial KATP Channel Subunits and Energy Metabolism Circ. Res., February 1, 2008; 102(2): e20 - e35. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. S. Lowe, O. Palygin, N. Bhasin, T. J. Hund, P. A. Boyden, E. Shibata, M. E. Anderson, and P. J. Mohler Voltage-gated Nav channel targeting in the heart requires an ankyrin-G dependent cellular pathway J. Cell Biol., January 10, 2008; 180(1): 173 - 186. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. K. Panama, M. McLerie, and A. N. Lopatin Heterogeneity of IK1 in the mouse heart Am J Physiol Heart Circ Physiol, December 1, 2007; 293(6): H3558 - H3567. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Gaborit, S. Le Bouter, V. Szuts, A. Varro, D. Escande, S. Nattel, and S. Demolombe Regional and tissue specific transcript signatures of ion channel genes in the non-diseased human heart J. Physiol., July 15, 2007; 582(2): 675 - 693. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Tikku, Y. Epshtein, H. Collins, A. J. Travis, G. H. Rothblat, and I. Levitan Relationship between Kir2.1/Kir2.3 activity and their distributions between cholesterol-rich and cholesterol-poor membrane domains Am J Physiol Cell Physiol, July 1, 2007; 293(1): C440 - C450. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Hassinen, V. Paajanen, J. Haverinen, H. Eronen, and M. Vornanen Cloning and expression of cardiac Kir2.1 and Kir2.2 channels in thermally acclimated rainbow trout Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2007; 292(6): R2328 - R2339. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Kristensen, T. Hansen, and C. Juel Membrane proteins involved in potassium shifts during muscle activity and fatigue Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2006; 290(3): R766 - R772. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. K. Panama and A. N. Lopatin Differential polyamine sensitivity in inwardly rectifying Kir2 potassium channels J. Physiol., March 1, 2006; 571(2): 287 - 302. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Fauconnier, A. Lacampagne, J.-M. Rauzier, G. Vassort, and S. Richard Ca2+-dependent reduction of IK1 in rat ventricular cells: A novel paradigm for arrhythmia in heart failure? Cardiovasc Res, November 1, 2005; 68(2): 204 - 212. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Fang, G. Schram, V. G. Romanenko, C. Shi, L. Conti, C. A. Vandenberg, P. F. Davies, S. Nattel, and I. Levitan Functional expression of Kir2.x in human aortic endothelial cells: the dominant role of Kir2.2 Am J Physiol Cell Physiol, November 1, 2005; 289(5): C1134 - C1144. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Rose, A. A. Armoundas, Y. Tian, D. DiSilvestre, M. Burysek, V. Halperin, B. O'Rourke, D. A. Kass, E. Marban, and G. F. Tomaselli Molecular correlates of altered expression of potassium currents in failing rabbit myocardium Am J Physiol Heart Circ Physiol, May 1, 2005; 288(5): H2077 - H2087. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. S. Dhamoon, S. V. Pandit, F. Sarmast, K. R. Parisian, P. Guha, Y. Li, S. Bagwe, S. M. Taffet, and J. M.B. Anumonwo Unique Kir2.x Properties Determine Regional and Species Differences in the Cardiac Inward Rectifier K+ Current Circ. Res., May 28, 2004; 94(10): 1332 - 1339. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. R. Ehrlich, M. Pourrier, M. Weerapura, N. Ethier, A. M. Marmabachi, T. E. Hebert, and S. Nattel KvLQT1 Modulates the Distribution and Biophysical Properties of HERG: A NOVEL {alpha}-SUBUNIT INTERACTION BETWEEN DELAYED RECTIFIER CURRENTS J. Biol. Chem., January 9, 2004; 279(2): 1233 - 1241. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Schram, M. Pourrier, Z. Wang, M. White, and S. Nattel Barium block of Kir2 and human cardiac inward rectifier currents: evidence for subunit-heteromeric contribution to native currents Cardiovasc Res, August 1, 2003; 59(2): 328 - 338. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
