JBC

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

A more recent version of this article appeared on October 17, 2003
This Article
Right arrow Full Text (Accepted Manuscript)
Right arrow All Versions of this Article:
278/42/40890    most recent
M304235200v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Fernandez, F. R.
Right arrow Articles by Turner, R. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Fernandez, F. R.
Right arrow Articles by Turner, R. W.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

Papers In Press, published online ahead of print August 15, 2003
J. Biol. Chem, 10.1074/jbc.M304235200
Submitted on April 22, 2003
Revised on August 11, 2003
Accepted on August 15, 2003

Inactivation of Kv3.3 potassium channels in heterologous expression systems

Fernando R. Fernandez, Ezequiel Morales, Asim J. Rashid, Robert J. Dunn, and Ray W. Turner

Cell Biology and Anatomy, University of Calgary, Faculty of Medicine, Calgary, Alberta T2N 4N1

Corresponding Author: rwturner{at}ucalgary.ca

Kv3.3 K+ channels are believed to incorporate an N-terminal domain to produce an intermediate rate of inactivation relative to the fast inactivating K+ channels Kv3.4 and Kv1.4. The rate of Kv3.3 inactivation has, however, been difficult to establish given problems in obtaining consistent rates of inactivation in expression systems. This study characterized the properties of AptKv3.3, the teleost homologue of Kv3.3, when expressed in Chinese Hamster Ovary (CHO) or Human Embryonic Kidney (HEK) cells. We show that the properties of AptKv3.3 differ significantly between CHO and HEK cells, with the largest difference occurring in the rate and voltage-dependence of inactivation. While AptKv3.3 in CHO cells showed a fast and voltage-dependent rate of inactivation consistent with N-type inactivation, currents in HEK cells showed rates of inactivation that were voltage-independent and more consistent with a slower C-type inactivation. Examination of the mRNA sequence revealed that the first methionine start site had a weak Kozak consensus sequence, suggesting that the lack of inactivation in HEK cells could be due to translation at a second methionine start site downstream of the N-terminal coding region. Mutating the nucleotide sequence surrounding the first methionine start site to one more closely resembling a Kozak consensus sequence produced currents that inactivated with a fast and voltage-dependent rate of inactivation in both CHO and HEK cells. These results indicate that under the appropriate conditions Kv3.3 channels can exhibit fast and reliable inactivation that approaches that more typically expected of "A"-type K+ currents.


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:


Home page
 J. Biol. Chem.Home page
R. Desai, J. Kronengold, J. Mei, S. A. Forman, and L. K. Kaczmarek
Protein Kinase C Modulates Inactivation of Kv3.3 Channels
J. Biol. Chem., August 8, 2008; 283(32): 22283 - 22294.
[Abstract] [Full Text] [PDF]

Home page
 J. Gen. Physiol.Home page
R. K. Finol-Urdaneta, N. Struver, and H. Terlau
Molecular and Functional Differences between Heart mKv1.7 Channel Isoforms
J. Gen. Physiol., June 26, 2006; 128(1): 133 - 145.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
F. R. Fernandez, W. H. Mehaffey, and R. W. Turner
Dendritic Na+ Current Inactivation Can Increase Cell Excitability By Delaying a Somatic Depolarizing Afterpotential
J Neurophysiol, December 1, 2005; 94(6): 3836 - 3848.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
L. K. Bekar, M. E. Loewen, K. Cao, X. Sun, J. Leis, R. Wang, G. W. Forsyth, and W. Walz
Complex Expression and Localization of Inactivating Kv Channels in Cultured Hippocampal Astrocytes
J Neurophysiol, March 1, 2005; 93(3): 1699 - 1709.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
F. R. Fernandez, W. H. Mehaffey, M. L. Molineux, and R. W. Turner
High-Threshold K+ Current Increases Gain by Offsetting a Frequency-Dependent Increase in Low-Threshold K+ Current
J. Neurosci., January 12, 2005; 25(2): 363 - 371.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
T. Shevchenko, R. Teruyama, and W. E. Armstrong
High-Threshold, Kv3-Like Potassium Currents in Magnocellular Neurosecretory Neurons and Their Role in Spike Repolarization
J Neurophysiol, November 1, 2004; 92(5): 3043 - 3055.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
A. Lewis, Z. A. McCrossan, and G. W. Abbott
MinK, MiRP1, and MiRP2 Diversify Kv3.1 and Kv3.2 Potassium Channel Gating
J. Biol. Chem., February 27, 2004; 279(9): 7884 - 7892.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
 All ASBMB Journals   Molecular and Cellular Proteomics 
 Journal of Lipid Research   ASBMB Today 
Copyright © 2003 by the American Society for Biochemistry and Molecular Biology.