What question did this study set out to answer?

This research aims to understand how different divalent cations like Ca2+ and Ba2+ affect the permeation and gating of CaV3.1 T-type calcium channels.

July 28, 2008The Journal of General PhysiologyOpen Access

Permeation and Gating in CaV3.1 (α1G) T-type Calcium Channels Effects of Ca2+, Ba2+, Mg2+, and Na+

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Population

Ca(V)3.1 T-type calcium channels stably expressed in HEK 293 cells

Design

Preclinical

Authors

NKNilofar KhanDefence Institute of Physiology and Allied Sciences IGI. Patrick GrayWitten/Herdecke University COCarlos A. Obejero‐PazPalo Alto University

Discussion

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Implication

No immediate implications for T-type channel therapies; leaves open mechanistic questions on Ba2+ effects in native cardiac channels.

Key Points

This research aims to understand how different divalent cations like Ca2+ and Ba2+ affect the permeation and gating of CaV3.1 T-type calcium channels.
Recorded whole-cell currents from HEK 293 cells expressing CaV3.1 channels.
Varying concentrations of Ca2+ and Ba2+ while assessing current-voltage relationships.
Analyzed chord conductances and determined block and permeation characteristics.
P(Ca)/P(Na) was measured at 87, and P(Ca)/P(Ba) at 2, indicating preference for calcium over sodium and barium.
The apparent K(d) values for Ca2+ and Ba2+ blockage were similar, 3 μM vs. 4 μM respectively at -30 mV.
Inward currents inactivated 35% faster with Ba2+ compared to Ca2+ or Na+, suggesting Ba2+ accelerates inactivation.

Structured PICO

Population

Ca(V)3.1 T-type calcium channels stably expressed in HEK 293 cells

Intervention

Varying concentrations of Ca(2+), Ba(2+), Mg(2+), and Na+ (100 nM to 110 mM)

Outcome

Concentration dependence of currents, permeation, and gating (instantaneous current-voltage relationships, reversal potentials, chord conductances, and inactivation kinetics)surrogate

In CaV3.1 T-type calcium channels, voltage strongly affects the concentration dependence of block but not permeation for Ca2+ or Ba2+, and surface charge selectivity differs between calcium channel families.

Cite This Study

Khan et al. (2008) studied this question.

synapsesocial.com/papers/6a70a2fbe36a167817e274c4 https://doi.org/10.1085/jgp.200809986

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Permeation and Gating in CaV3.1 (α1G) T-type Calcium Channels Effects of Ca2+, Ba2+, Mg2+, and Na+

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Permeation and Gating in CaV3.1 (α1G) T-type Calcium Channels Effects of Ca2+, Ba2+, Mg2+, and Na+

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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