User:Lukáš Hodboď
From Proteopedia
2k21
Structural highlights
Disease[KCNE1_HUMAN] Mutations in KCNE1 cause long QT syndrome type 5 (LQT5) [MIM:613695]. Congenital long QT syndrome is electrocardiographically characterized by a prolonged QT interval and polymorphic ventricular arrhythmias (torsade de pointes). These cardiac arrhythmias may result in recurrent syncope, seizure, or sudden death. [1] Mutations in KCNE1 are the cause of Jervell and Lange-Nielsen syndrome type 2 (JLNS2)[MIM:612347]. The Jervell and Lange-Nielsen syndrome is an autosomal recessive disorder characterized by congenital deafness, prolongation of the QT interval, syncopal attacks due to ventricular arrhythmias, and a high risk of sudden death. [2] These mutations inhibit the ability of KCNE1 to form fully functional IKs channels. Mutation that disrupts the N5 sequon of KCNE1 protein hinders its glycosylation, leading to the formation of channels that are unable of proper cell surface expression due to defect in anterograde trafficking. [3] [4] [5] [6] [7] [8] [9] [10][11] Mutations in KCNE1 may be a cause for hightened susceptibility to the Noise-Induced Hearing Loss. [12] FunctionKCNE1 and KVLQT1 protein products coassemble to form the cardiac I(Ks) channel. [13] Through the formation of heteromeric channel complexes, KCNE1 is central to the control of the heart rate and rhythm. [14] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedKCNE1 is a single-span membrane protein that modulates the voltage-gated potassium channel KCNQ1 (K V7.1) by slowing activation and enhancing channel conductance to generate the slow delayed rectifier current ( I Ks) that is critical for the repolarization phase of the cardiac action potential. Perturbation of channel function by inherited mutations in KCNE1 or KCNQ1 results in increased susceptibility to cardiac arrhythmias and sudden death with or without accompanying deafness. Here, we present the three-dimensional structure of KCNE1. The transmembrane domain (TMD) of KCNE1 is a curved alpha-helix and is flanked by intra- and extracellular domains comprised of alpha-helices joined by flexible linkers. Experimentally restrained docking of the KCNE1 TMD to a closed state model of KCNQ1 suggests that KCNE1 slows channel activation by sitting on and restricting the movement of the S4-S5 linker that connects the voltage sensor to the pore domain. We postulate that this is an adhesive interaction that must be disrupted before the channel can be opened in response to membrane depolarization. Docking to open KCNQ1 indicates that the extracellular end of the KCNE1 TMD forms an interface with an intersubunit cleft in the channel that is associated with most known gain-of-function disease mutations. Binding of KCNE1 to this "gain-of-function cleft" may explain how it increases conductance and stabilizes the open state. These working models for the KCNE1-KCNQ1 complexes may be used to formulate testable hypotheses for the molecular bases of disease phenotypes associated with the dozens of known inherited mutations in KCNE1 and KCNQ1. Structure of KCNE1 and implications for how it modulates the KCNQ1 potassium channel.,Kang C, Tian C, Sonnichsen FD, Smith JA, Meiler J, George AL Jr, Vanoye CG, Kim HJ, Sanders CR Biochemistry. 2008 Aug 5;47(31):7999-8006. Epub 2008 Jul 9. PMID:18611041[15] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Human | George, A L | Kang, C | Kim, H | Meiler, J | Sanders, C R | Smith, J A | Sonnichsen, F D | Tian, C | Vanoye, C G | Auxilliary subunit | Ion transport | Ionic channel | Kcne1 | Membrane protein | Micelle | Mink | Potassium channel | Potassium transport | Transmembrane | Transport | Voltage-gated channel