Coexpression of cloned α(1B), β(2a), and α2/δ subunits produces non-inactivating calcium currents similar to those found in bovine chromaffin cells

Anne L. Cahill, Joyce H. Hurley, Aaron P. Fox

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

Chromaffin cells express N-type calcium channels identified on the basis of their high sensitivity to block by ω-conotoxin GVIA (ω-CgTx GVIA). In contrast to neuronal N-type calcium currents that inactivate during long depolarizations and that require negative holding potentials to remove inactivation, many chromaffin cells exhibit N-type calcium channel currents that show little inactivation during maintained depolarizations and that exhibit no decrease in channel availability at depolarized holding potentials. N-type calcium channels are thought to be produced by combination of the pore-forming α(1B) subunit and accessory β and α2/δ subunits. To examine the molecular composition of the non-inactivating N-type calcium channel, we cloned the α(1B) and accessory β(β(1b), β(1c), β(2a), β(2b), and β(3a)) subunits found in bovine chromaffin cells. Expression of the subunits in either Xenopus oocytes or human embryonic kidney 293 cells produced high-threshold calcium currents that were blocked by ω-CgTx GVIA. Coexpression of bovine α(1B) with β(1b), β(1c), β(2b.) or β(3a) produced currents that were holding potential dependent. In contrast, coexpression of bovine α(1B) with β(2a) produced holding potential-independent calcium currents that closely mimicked native non-inactivating currents, suggesting that non-inactivating N-type channels consist of bovine α(1B), α2/δ, and β(2a).

Original languageEnglish (US)
Pages (from-to)1685-1693
Number of pages9
JournalJournal of Neuroscience
Volume20
Issue number5
StatePublished - Mar 1 2000

Fingerprint

N-Type Calcium Channels
Chromaffin Cells
Calcium
Conotoxins
Xenopus
Oocytes
Kidney

Keywords

  • Chromaffin cells
  • N-type Calcium channel
  • Non-inactivating calcium current
  • Voltage-dependent calcium channel
  • α(1B) subunit
  • β subunits

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Coexpression of cloned α(1B), β(2a), and α2/δ subunits produces non-inactivating calcium currents similar to those found in bovine chromaffin cells. / Cahill, Anne L.; Hurley, Joyce H.; Fox, Aaron P.

In: Journal of Neuroscience, Vol. 20, No. 5, 01.03.2000, p. 1685-1693.

Research output: Contribution to journalArticle

@article{c142e6c51d6442ebbdc3eb2087630582,
title = "Coexpression of cloned α(1B), β(2a), and α2/δ subunits produces non-inactivating calcium currents similar to those found in bovine chromaffin cells",
abstract = "Chromaffin cells express N-type calcium channels identified on the basis of their high sensitivity to block by ω-conotoxin GVIA (ω-CgTx GVIA). In contrast to neuronal N-type calcium currents that inactivate during long depolarizations and that require negative holding potentials to remove inactivation, many chromaffin cells exhibit N-type calcium channel currents that show little inactivation during maintained depolarizations and that exhibit no decrease in channel availability at depolarized holding potentials. N-type calcium channels are thought to be produced by combination of the pore-forming α(1B) subunit and accessory β and α2/δ subunits. To examine the molecular composition of the non-inactivating N-type calcium channel, we cloned the α(1B) and accessory β(β(1b), β(1c), β(2a), β(2b), and β(3a)) subunits found in bovine chromaffin cells. Expression of the subunits in either Xenopus oocytes or human embryonic kidney 293 cells produced high-threshold calcium currents that were blocked by ω-CgTx GVIA. Coexpression of bovine α(1B) with β(1b), β(1c), β(2b.) or β(3a) produced currents that were holding potential dependent. In contrast, coexpression of bovine α(1B) with β(2a) produced holding potential-independent calcium currents that closely mimicked native non-inactivating currents, suggesting that non-inactivating N-type channels consist of bovine α(1B), α2/δ, and β(2a).",
keywords = "Chromaffin cells, N-type Calcium channel, Non-inactivating calcium current, Voltage-dependent calcium channel, α(1B) subunit, β subunits",
author = "Cahill, {Anne L.} and Hurley, {Joyce H.} and Fox, {Aaron P.}",
year = "2000",
month = "3",
day = "1",
language = "English (US)",
volume = "20",
pages = "1685--1693",
journal = "Journal of Neuroscience",
issn = "0270-6474",
publisher = "Society for Neuroscience",
number = "5",

}

TY - JOUR

T1 - Coexpression of cloned α(1B), β(2a), and α2/δ subunits produces non-inactivating calcium currents similar to those found in bovine chromaffin cells

AU - Cahill, Anne L.

AU - Hurley, Joyce H.

AU - Fox, Aaron P.

PY - 2000/3/1

Y1 - 2000/3/1

N2 - Chromaffin cells express N-type calcium channels identified on the basis of their high sensitivity to block by ω-conotoxin GVIA (ω-CgTx GVIA). In contrast to neuronal N-type calcium currents that inactivate during long depolarizations and that require negative holding potentials to remove inactivation, many chromaffin cells exhibit N-type calcium channel currents that show little inactivation during maintained depolarizations and that exhibit no decrease in channel availability at depolarized holding potentials. N-type calcium channels are thought to be produced by combination of the pore-forming α(1B) subunit and accessory β and α2/δ subunits. To examine the molecular composition of the non-inactivating N-type calcium channel, we cloned the α(1B) and accessory β(β(1b), β(1c), β(2a), β(2b), and β(3a)) subunits found in bovine chromaffin cells. Expression of the subunits in either Xenopus oocytes or human embryonic kidney 293 cells produced high-threshold calcium currents that were blocked by ω-CgTx GVIA. Coexpression of bovine α(1B) with β(1b), β(1c), β(2b.) or β(3a) produced currents that were holding potential dependent. In contrast, coexpression of bovine α(1B) with β(2a) produced holding potential-independent calcium currents that closely mimicked native non-inactivating currents, suggesting that non-inactivating N-type channels consist of bovine α(1B), α2/δ, and β(2a).

AB - Chromaffin cells express N-type calcium channels identified on the basis of their high sensitivity to block by ω-conotoxin GVIA (ω-CgTx GVIA). In contrast to neuronal N-type calcium currents that inactivate during long depolarizations and that require negative holding potentials to remove inactivation, many chromaffin cells exhibit N-type calcium channel currents that show little inactivation during maintained depolarizations and that exhibit no decrease in channel availability at depolarized holding potentials. N-type calcium channels are thought to be produced by combination of the pore-forming α(1B) subunit and accessory β and α2/δ subunits. To examine the molecular composition of the non-inactivating N-type calcium channel, we cloned the α(1B) and accessory β(β(1b), β(1c), β(2a), β(2b), and β(3a)) subunits found in bovine chromaffin cells. Expression of the subunits in either Xenopus oocytes or human embryonic kidney 293 cells produced high-threshold calcium currents that were blocked by ω-CgTx GVIA. Coexpression of bovine α(1B) with β(1b), β(1c), β(2b.) or β(3a) produced currents that were holding potential dependent. In contrast, coexpression of bovine α(1B) with β(2a) produced holding potential-independent calcium currents that closely mimicked native non-inactivating currents, suggesting that non-inactivating N-type channels consist of bovine α(1B), α2/δ, and β(2a).

KW - Chromaffin cells

KW - N-type Calcium channel

KW - Non-inactivating calcium current

KW - Voltage-dependent calcium channel

KW - α(1B) subunit

KW - β subunits

UR - http://www.scopus.com/inward/record.url?scp=0034161546&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034161546&partnerID=8YFLogxK

M3 - Article

C2 - 10684870

AN - SCOPUS:0034161546

VL - 20

SP - 1685

EP - 1693

JO - Journal of Neuroscience

JF - Journal of Neuroscience

SN - 0270-6474

IS - 5

ER -