| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, USA
* To whom correspondence should be addressed. E-mail: criss{at}cellbio.emory.edu.
Ca2+-activated Cl channels (ClCa) were characterized biophysically and pharmacologically in a mouse kidney inner medullary collecting duct cell line, IMCD-K2. Whole-cell recording was performed with symmetrical NMDG-Cl in the intracellular and extracellular solutions and [Ca2+]i was adjusted with Ca2+-EGTA buffers. The amplitude of the current was dependent on intracellular [Ca2+]. [Ca2+]i <800nM activated strongly outwardly rectifying Cl currents while high Ca2+ [21 µM] elicited time-independent currents that did not rectify. The currents activated at low [Ca2+] exhibited time-dependent activation and deactivation. The affinity of the channel for Ca2+ was voltage-dependent. The EC50 for Ca2+ was ~0.4 µM at +100mV and ~1.0 µM at -100mV. The Cl channel blocker NFA in the bath equally inhibited both inward and outward currents reversibly with Ki = 7.6 µM. DIDS, DPC and A9C reversibly inhibited outward currents in a voltage-dependent manner. DTT slowly inhibited the currents but tamoxifen did not inhibit. Comparing the biophysical and pharmacological properties, we conclude that IMCD-K2 cells express the same type of ClCa channels as those we have described in detail in Xenopus oocytes.
This article has been cited by other articles:
|
|
 |
|
  L. Ferrera, A. Caputo, I. Ubby, E. Bussani, O. Zegarra-Moran, R. Ravazzolo, F. Pagani, and L. J. V. Galietta Regulation of TMEM16A Chloride Channel Properties by Alternative Splicing J. Biol. Chem., November 27, 2009; 284(48): 33360 - 33368. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Barro Soria, M. Spitzner, R. Schreiber, and K. Kunzelmann Bestrophin-1 Enables Ca2+-activated Cl- Conductance in Epithelia J. Biol. Chem., October 23, 2009; 284(43): 29405 - 29412. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Günzel, S. Amasheh, S. Pfaffenbach, J. F. Richter, P. J. Kausalya, W. Hunziker, and M. Fromm Claudin-16 affects transcellular Cl\#8722; secretion in MDCK cells J. Physiol., August 1, 2009; 587(15): 3777 - 3793. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Aldehni, M. Spitzner, J. R. Martins, R. Barro-Soria, R. Schreiber, and K. Kunzelmann Bestrophin 1 Promotes Epithelial-to-mesenchymal Transition of Renal Collecting Duct Cells J. Am. Soc. Nephrol., July 1, 2009; 20(7): 1556 - 1564. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. C. Hartzell, K. Yu, Q. Xiao, L.-T. Chien, and Z. Qu Anoctamin/TMEM16 family members are Ca2+-activated Cl\#8722; channels J. Physiol., May 15, 2009; 587(10): 2127 - 2139. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. J. Bolivar, D. Tapia, G. Arenas, M. Castanon-Arreola, H. Torres, and E. Galarraga A hyperpolarization-activated, cyclic nucleotide-gated, (Ih-like) cationic current and HCN gene expression in renal inner medullary collecting duct cells Am J Physiol Cell Physiol, April 1, 2008; 294(4): C893 - C906. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. E. Angermann, A. R. Sanguinetti, J. L. Kenyon, N. Leblanc, and I. A. Greenwood Mechanism of the Inhibition of Ca2+-Activated Cl- Currents by Phosphorylation in Pulmonary Arterial Smooth Muscle Cells J. Gen. Physiol., June 26, 2006; 128(1): 73 - 87. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. H. Boese, O. Aziz, N. L. Simmons, and M. A. Gray Kinetics and regulation of a Ca2+-activated Cl- conductance in mouse renal inner medullary collecting duct cells Am J Physiol Renal Physiol, April 1, 2004; 286(4): F682 - F692. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
