Article
The Effect of α2-δ and Other Accessory Subunits on Expression and Properties of the Calcium Channel α1G
The Journal of Physiology
Document Type
Article
Publication Date
8-1-1999
Disciplines
Abstract
- The effect has been examined of the accessory α2-δ and β subunits on the properties of α1G currents expressed in monkey COS-7 cells and Xenopus oocytes.
- In immunocytochemical experiments, the co-expression of α2-δ increased plasma membrane localization of expressed α1G and conversely, the heterologous expression of α1G increased immunostaining for endogenous α2-δ, suggesting an interaction between the two subunits.
- Heterologous expression of α2-δ together with α1G in COS-7 cells increased the amplitude of expressed α1G currents by about 2-fold. This finding was confirmed in the Xenopus oocyte expression system. The truncated δ construct did not increase α1G current amplitude, or increase its plasma membrane expression. This indicates that it is the exofacial α2 domain that is involved in the enhancement by α2-δ.
- β1b also produced an increase of functional expression of α1G, either in the absence or the presence of heterologously expressed α2-δ, whereas the other β subunits had much smaller effects.
- None of the accessory subunits had any marked influence on the voltage dependence or kinetics of the expressed α1G currents. These results therefore suggest that α2-δ and β1b interact with α1G to increase trafficking of, or stabilize, functional α1G channels expressed at the plasma membrane.
DOI
10.1111/j.1469-7793.1999.0035o.x
Citation Information
Annette C. Dolphin, Christopher N. Wyatt, J. Richards, R. E. Beattie, et al.. "The Effect of α2-δ and Other Accessory Subunits on Expression and Properties of the Calcium Channel α1G" The Journal of Physiology Vol. 519 Iss. 1 (1999) p. 35 - 45 ISSN: 0022-3751 Available at: http://works.bepress.com/christopher_wyatt/57/