Xenbase is undergoing scheduled maintenance Wednesday, June 14 and Thursday, June 15, 2023. Xenbase will be unavailable on those days.

Click on this message to dismiss it.
Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
Neuron 2003 Sep 25;401:15-23. doi: 10.1016/s0896-6273(03)00570-1.
Show Gene links Show Anatomy links

Charybdotoxin binding in the I(Ks) pore demonstrates two MinK subunits in each channel complex.

Chen H , Kim LA , Rajan S , Xu S , Goldstein SA .

I(Ks) voltage-gated K(+) channels contain four pore-forming KCNQ1 subunits and MinK accessory subunits in a number that has been controversial. Here, I(Ks) channels assembled naturally by monomer subunits are compared to those with linked subunits that force defined stoichiometries. Two strategies that exploit charybdotoxin (CTX)-sensitive subunit variants are applied. First, CTX on rate, off rate, and equilibrium affinity are found to be the same for channels of monomers and those with a fixed 2:4 MinK:KCNQ1 valence. Second, 3H-CTX and an antibody are used to directly quantify channels and MinK subunits, respectively, showing 1.97 +/- 0.07 MinK per I(Ks) channel. Additional MinK subunits do not enter channels of monomeric subunits or those with fixed 2:4 valence. We conclude that two MinK subunits are necessary, sufficient, and the norm in I(Ks) channels. This stoichiometry is expected for other K(+) channels that contain MinK or MinK-related peptides (MiRPs).

PubMed ID: 14527430
Article link: Neuron

Species referenced: Xenopus
Genes referenced: kcne1 kcnq1 mink1 vsig1