![]() |
|
|
Vol. 16, Issue 8, 3538-3551, August 2005
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229
Submitted September 28, 2004;
Revised April 20, 2005;
Accepted May 11, 2005
Monitoring Editor: Guido Guidotti
Calmodulin modulation of ion channels has emerged as a prominent theme in biology. The sensitivity of KCNQ15 K+ channels to modulation by Ca2+/calmodulin (CaM) was studied using patch-clamp, Ca2+ imaging, and biochemical and pharmacological approaches. Coexpression of CaM in Chinese hamster ovary (CHO) cells strongly reduced currents of KCNQ2, KCNQ4, and KCNQ5, but not KCNQ1 or KCNQ3. In simultaneous current recording/Ca2+ imaging experiments, CaM conferred Ca2+ sensitivity to KCNQ4 and KCNQ5, but not to KCNQ1, KCNQ3, or KCNQ1/KCNE1 channels. A chimera constructed from the carboxy terminus of KCNQ4 and the rest KCNQ1 displayed Ca2+ sensitivity similar to KCNQ4. Chimeras constructed from different lengths of the KCNQ4 carboxy terminal and the rest KCNQ3 localized a region that confers sensitivity to Ca2+/CaM. Lobe-specific mutations of CaM revealed that its amino-terminal lobe mediates the Ca2+ sensitivity of the KCNQ/CaM complex. The site of CaM action within the channel carboxy terminus overlaps with that of the KCNQ opener N-ethylmaleimide (NEM). We found that CaM overexpression reduced NEM augmentation of KCNQ2, KCNQ4, and KCNQ5, and NEM pretreatment reduced Ca2+/CaM-mediated suppression of M current in sympathetic neurons by bradykinin. We propose that two functionally distinct types of carboxy termini underlie the observed differences among this channel family.
Address correspondence to: Mark S. Shapiro (shapirom{at}uthscsa.edu).
This article has been cited by other articles:
![]() |
M. Bal, J. Zhang, C. C. Hernandez, O. Zaika, and M. S. Shapiro Ca2+/Calmodulin Disrupts AKAP79/150 Interactions with KCNQ (M-Type) K+ Channels J. Neurosci., February 10, 2010; 30(6): 2311 - 2323. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Caspi, F. Benninger, and Y. Yaari KV7/M Channels Mediate Osmotic Modulation of Intrinsic Neuronal Excitability J. Neurosci., September 9, 2009; 29(36): 11098 - 11111. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Asada, J. Kurokawa, and T. Furukawa Redox- and Calmodulin-dependent S-Nitrosylation of the KCNQ1 Channel J. Biol. Chem., February 27, 2009; 284(9): 6014 - 6020. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Bal, J. Zhang, O. Zaika, C. C. Hernandez, and M. S. Shapiro Homomeric and Heteromeric Assembly of KCNQ (Kv7) K+ Channels Assayed by Total Internal Reflection Fluorescence/Fluorescence Resonance Energy Transfer and Patch Clamp Analysis J. Biol. Chem., November 7, 2008; 283(45): 30668 - 30676. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. R. Mackie and K. L. Byron Cardiovascular KCNQ (Kv7) Potassium Channels: Physiological Regulators and New Targets for Therapeutic Intervention Mol. Pharmacol., November 1, 2008; 74(5): 1171 - 1179. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. E. Linley, K. Rose, M. Patil, B. Robertson, A. N. Akopian, and N. Gamper Inhibition of M Current in Sensory Neurons by Exogenous Proteases: A Signaling Pathway Mediating Inflammatory Nociception J. Neurosci., October 29, 2008; 28(44): 11240 - 11249. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Heitzmann and R. Warth Physiology and Pathophysiology of Potassium Channels in Gastrointestinal Epithelia Physiol Rev, July 1, 2008; 88(3): 1119 - 1182. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Liu, H. Liang, L. Liu, and H. Zhang Phosphatidylinositol 4,5-bisphosphate hydrolysis mediates histamine-induced KCNQ/M current inhibition Am J Physiol Cell Physiol, July 1, 2008; 295(1): C81 - C91. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Jia, J. Bei, L. Rodat-Despoix, B. Liu, Q. Jia, P. Delmas, and H. Zhang NGF Inhibits M/KCNQ Currents and Selectively Alters Neuronal Excitability in Subsets of Sympathetic Neurons Depending on their M/KCNQ Current Background J. Gen. Physiol., June 1, 2008; 131(6): 575 - 587. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Bal, O. Zaika, P. Martin, and M. S. Shapiro Calmodulin binding to M-type K+ channels assayed by TIRF/FRET in living cells J. Physiol., May 1, 2008; 586(9): 2307 - 2320. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Haitin and B. Attali The C-terminus of Kv7 channels: a multifunctional module J. Physiol., April 1, 2008; 586(7): 1803 - 1810. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. C. Hernandez, O. Zaika, G. P. Tolstykh, and M. S. Shapiro Regulation of neural KCNQ channels: signalling pathways, structural motifs and functional implications J. Physiol., April 1, 2008; 586(7): 1811 - 1821. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Chen and Y. Yaari Spike Ca2+ influx upmodulates the spike afterdepolarization and bursting via intracellular inhibition of KV7/M channels J. Physiol., March 1, 2008; 586(5): 1351 - 1363. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Wiener, Y. Haitin, L. Shamgar, M. C. Fernandez-Alonso, A. Martos, O. Chomsky-Hecht, G. Rivas, B. Attali, and J. A. Hirsch The KCNQ1 (Kv7.1) COOH Terminus, a Multitiered Scaffold for Subunit Assembly and Protein Interaction J. Biol. Chem., February 29, 2008; 283(9): 5815 - 5830. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. A. Roepke, A. Malyala, M. A. Bosch, M. J. Kelly, and O. K. Ronnekleiv Estrogen Regulation of Genes Important for K+ Channel Signaling in the Arcuate Nucleus Endocrinology, October 1, 2007; 148(10): 4937 - 4951. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Gamper and M. S. Shapiro Target-specific PIP2 signalling: how might it work? J. Physiol., August 1, 2007; 582(3): 967 - 975. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. E. D. J. ter Keurs and P. A. Boyden Calcium and Arrhythmogenesis Physiol Rev, April 1, 2007; 87(2): 457 - 506. [Abstract] [Full Text] [PDF] |
||||
![]() |
Q. Jia, Z. Jia, Z. Zhao, B. Liu, H. Liang, and H. Zhang Activation of Epidermal Growth Factor Receptor Inhibits KCNQ2/3 Current through Two Distinct Pathways: Membrane PtdIns(4,5)P2 Hydrolysis and Channel Phosphorylation J. Neurosci., March 7, 2007; 27(10): 2503 - 2512. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. Zaika, L. S. Lara, N. Gamper, D. W. Hilgemann, D. B. Jaffe, and M. S. Shapiro Angiotensin II regulates neuronal excitability via phosphatidylinositol 4,5-bisphosphate-dependent modulation of Kv7 (M-type) K+ channels J. Physiol., August 15, 2006; 575(1): 49 - 67. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Ghosh, D. A. Nunziato, and G. S. Pitt KCNQ1 Assembly and Function Is Blocked by Long-QT Syndrome Mutations That Disrupt Interaction With Calmodulin Circ. Res., April 28, 2006; 98(8): 1048 - 1054. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Shamgar, L. Ma, N. Schmitt, Y. Haitin, A. Peretz, R. Wiener, J. Hirsch, O. Pongs, and B. Attali Calmodulin Is Essential for Cardiac IKS Channel Gating and Assembly: Impaired Function in Long-QT Mutations Circ. Res., April 28, 2006; 98(8): 1055 - 1063. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. S. Surti, L. Huang, Y. N. Jan, L. Y. Jan, and E. C. Cooper Identification by mass spectrometry and functional characterization of two phosphorylation sites of KCNQ2/KCNQ3 channels PNAS, December 6, 2005; 102(49): 17828 - 17833. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Li, N. Gamper, D. W. Hilgemann, and M. S. Shapiro Regulation of Kv7 (KCNQ) K+ Channel Open Probability by Phosphatidylinositol 4,5-Bisphosphate J. Neurosci., October 26, 2005; 25(43): 9825 - 9835. [Abstract] [Full Text] [PDF] |
||||