ABCC8 p.His160Ala
| Predicted by SNAP2: | A: N (72%), C: N (66%), D: N (57%), E: N (57%), F: N (82%), G: N (66%), I: N (82%), K: N (57%), L: N (82%), M: N (82%), N: N (82%), P: N (61%), Q: N (78%), R: N (82%), S: N (87%), T: N (78%), V: N (82%), W: N (57%), Y: N (93%), |
| Predicted by PROVEAN: | A: N, C: D, D: N, E: N, F: N, G: N, I: D, K: D, L: D, M: D, N: N, P: D, Q: N, R: D, S: N, T: D, V: D, W: D, Y: N, |
[switch to compact view]
Comments [show]
None has been submitted yet.
[hide] Two SUR1-specific histidine residues mandatory for... J Biol Chem. 2005 Mar 11;280(10):8793-9. Epub 2004 Dec 21. Bancila V, Cens T, Monnier D, Chanson F, Faure C, Dunant Y, Bloc A
Two SUR1-specific histidine residues mandatory for zinc-induced activation of the rat KATP channel.
J Biol Chem. 2005 Mar 11;280(10):8793-9. Epub 2004 Dec 21., [PMID:15613469]
Abstract [show]
Zinc at micromolar concentrations hyperpolarizes rat pancreatic beta-cells and brain nerve terminals by activating ATP-sensitive potassium channels (KATP). The molecular determinants of this effect were analyzed using insulinoma cell lines and cells transfected with either wild type or mutated KATP subunits. Zinc activated KATP in cells co-expressing rat Kir6.2 and SUR1 subunits, as in insulinoma cell lines. In contrast, zinc exerted an inhibitory action on SUR2A-containing cells. Therefore, SUR1 expression is required for the activating action of zinc, which also depended on extracellular pH and was blocked by diethyl pyrocarbonate, suggesting histidine involvement. The five SUR1-specific extracellular histidine residues were submitted to site-directed mutagenesis. Of them, two histidines (His-326 and His-332) were found to be critical for the activation of KATP by zinc, as confirmed by the double mutation H326A/H332A. In conclusion, zinc activates KATP by binding itself to extracellular His-326 and His-332 of the SUR1 subunit. Thereby zinc could exert a negative control on cell excitability and secretion process of pancreatic beta-and alpha-cells. In fact, we have recently shown that such a mechanism occurs in hippocampal mossy fibers, a brain region characterized, like the pancreas, by an important accumulation of zinc and a high density of SUR1-containing KATP.
Comments [show]
None has been submitted yet.
No. Sentence Comment
138 Mutations H11A, H160A, and H1273A had no effect, as zinc enhanced the KATP current in these clones to the same extent as in the wild type Kir6.2/SUR1 channels.
X
ABCC8 p.His160Ala 15613469:138:16
status: NEW175 Mutations H11A, H160A, and H1273A did not affect the zinc activation of KATP current, whose amplitude remained equal to that of the wild type rat SUR1/Kir6.2 clone.
X
ABCC8 p.His160Ala 15613469:175:16
status: NEW