spacer gif spacer gif spacer gif spacer gif spacer gif
 QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

This Article
Right arrow Full Text (PDF)
Right arrow References
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 Grigoriev, N. G.
Right arrow Articles by Spencer, A. N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Grigoriev, N. G.
Right arrow Articles by Spencer, A. N.

Journal of Experimental Biology, Vol 200, Issue 22 2919-2926, Copyright © 1997 by Company of Biologists


JOURNAL ARTICLES

Voltage sensing in jellyfish Shaker K+ channels

NG Grigoriev, JD Spafford, WJ Gallin and AN Spencer
Department of Biological Sciences, University of Alberta, Edmonton, Canada.

The S4 segment of the jellyfish (Polyorchis penicillatus) Shaker channel jShak1 contains only six positively charged motifs. All other Shaker channels, including the jellyfish Shaker channel jShak2, have seven charges in this segment. Despite their charge differences, both these jellyfish channels produce currents with activation and inactivation curves shifted by approximately +40 mV relative to other Shaker currents. Adding charge without changing segment length by mutating the N-terminal side of jShak1 S4 does not have a pronounced effect on channel activation properties. Adding the positively charged motif RIF on the N-terminal side of K294 (the homologue of K374 in Drosophila Shaker, which is a structurally critical residue) produced a large positive shift in both activation and inactivation without altering the slope of the activation curve of the channel. When IFR was added to the other side of K294, there was a small negative shift in activation and fast inactivation of the channel was prevented. Our results demonstrate that K294 divides the S4 segment into functionally different regions and that the voltage threshold for activation and inactivation of the channel is not determined by the total charge on S4.


This article has been cited by other articles:


Home page
J. Neurophysiol.Home page
T. L. Klassen, S. D. Buckingham, D. M. Atherton, J. B. Dacks, W. J. Gallin, and A. N. Spencer
Atypical Phenotypes From Flatworm Kv3 Channels
J Neurophysiol, May 1, 2006; 95(5): 3035 - 3046.
[Abstract] [Full Text] [PDF]


Home page
J. Exp. Biol.Home page
I. Inoue, I. Tsutsui, and Q. Bone
Long-lasting potassium channel inactivation in myoepithelial fibres is related to characteristics of swimming in diphyid siphonophores
J. Exp. Biol., December 15, 2005; 208(24): 4577 - 4584.
[Abstract] [Full Text] [PDF]


Home page
J. Exp. Biol.Home page
S. Buckingham and A. Spencer
K(+) currents in cultured neurones from a polyclad flatworm
J. Exp. Biol., January 10, 2000; 203(20): 3189 - 3198.
[Abstract]


Home page
J. Neurophysiol.Home page
N. G. Grigoriev, J. D. Spafford, and A. N. Spencer
Modulation of Jellyfish Potassium Channels by External Potassium Ions
J Neurophysiol, October 1, 1999; 82(4): 1728 - 1739.
[Abstract] [Full Text] [PDF]


Home page
J. Neurophysiol.Home page
N. G. Grigoriev, J. D. Spafford, and A. N. Spencer
Residues in a Jellyfish Shaker-Like Channel Involved in Modulation by External Potassium
J Neurophysiol, October 1, 1999; 82(4): 1740 - 1747.
[Abstract] [Full Text] [PDF]




© The Company of Biologists Ltd 1997