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-Structure paper
Title | Structural Basis of Human KCNQ1 Modulation and Gating. |
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Journal, issue, pages | Cell, Vol. 180, Issue 2, Page 340-347.e9, Year 2020 |
Publish date | Jan 23, 2020 |
Authors | Ji Sun / Roderick MacKinnon / |
PubMed Abstract | KCNQ1, also known as Kv7.1, is a voltage-dependent K channel that regulates gastric acid secretion, salt and glucose homeostasis, and heart rhythm. Its functional properties are regulated in a tissue- ...KCNQ1, also known as Kv7.1, is a voltage-dependent K channel that regulates gastric acid secretion, salt and glucose homeostasis, and heart rhythm. Its functional properties are regulated in a tissue-specific manner through co-assembly with beta subunits KCNE1-5. In non-excitable cells, KCNQ1 forms a complex with KCNE3, which suppresses channel closure at negative membrane voltages that otherwise would close it. Pore opening is regulated by the signaling lipid PIP2. Using cryoelectron microscopy (cryo-EM), we show that KCNE3 tucks its single-membrane-spanning helix against KCNQ1, at a location that appears to lock the voltage sensor in its depolarized conformation. Without PIP2, the pore remains closed. Upon addition, PIP2 occupies a site on KCNQ1 within the inner membrane leaflet, which triggers a large conformational change that leads to dilation of the pore's gate. It is likely that this mechanism of PIP2 activation is conserved among Kv7 channels. |
External links | Cell / PubMed:31883792 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.1 - 3.9 Å |
Structure data | EMDB-20965, PDB-6uzz: EMDB-20966, PDB-6v00: EMDB-20967, PDB-6v01: |
Chemicals | ChemComp-CA: ChemComp-PT5: |
Source |
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Keywords | MEMBRANE PROTEIN / potassium channel / KCNQ1 / CaM |