You can manage bookmarks using lists, please log in to your user account for this.
Media type:
E-Article
Title:
The α1ECalcium Channel Exhibits Permeation Properties Similar to Low-Voltage-Activated Calcium Channels
Contributor:
Bourinet, Emmanuel;
Zamponi, Gerald W.;
Stea, Anthony;
Soong, Tuck W.;
Lewis, Bertram A.;
Jones, Lisa P.;
Yue, David T.;
Snutch, Terry P.
Published:
Society for Neuroscience, 1996
Published in:
The Journal of Neuroscience, 16 (1996) 16, Seite 4983-4993
Language:
English
DOI:
10.1523/jneurosci.16-16-04983.1996
ISSN:
0270-6474;
1529-2401
Origination:
Footnote:
Description:
The physiological and pharmacological properties of the α1Ecalcium (Ca) channel subtype do not exactly match any of the established categories described for native neuronal Ca currents. Many of the key diagnostic features used to assign cloned Ca channels to their native counterparts, however, are dependent on a number of factors, including cellular environment, β subunit coexpression, and modulation by second messengers and G-proteins. Here, by examining the intrinsic pore characteristics of a family of transiently expressed neuronal Ca channels, we demonstrate that the permeation properties of α1Eclosely resemble those described for a subset of low-threshold Ca channels. The α1A(P-/Q-type), α1B(N-type), and α1C(L-type) high-threshold Ca channels all exhibit larger whole-cell currents with barium (Ba) as the charge carrier as compared with Ca or strontium (Sr). In contrast, macroscopic α1Ecurrents are largest in Sr, followed by Ca and then Ba. The unique permeation properties of α1Eare maintained at the single-channel level, are independent of the nature of the expression system, and are not affected by coexpression of α2and β subunits. Overall, the permeation characteristics of α1Eare distinct from those described for R-type currents and share some similarities with native low-threshold Ca channels.