Pathophysiological and Pharmacological Characteristics of KCNJ5 157-159delITE Somatic Mutation in Aldosterone-Producing Adenomas

Mutated channelopathy could play important roles in the pathogenesis of aldosterone-producing adenoma (APA). In this study, we identified a somatic mutation, KCNJ5 157-159delITE, and reported its immunohistological, pathophysiological and pharmacological characteristics. We conducted patch-clamp experiments on HEK293T cells and experiments on expression of aldosterone synthase (CYP11B2) and aldosterone secretion in HAC15 cells to evaluate electrophysiological and functional properties of this mutated KCNJ5. Immunohistochemistry was conducted to identify expressions of several steroidogenic enzymes. Macrolide antibiotics and a calcium channel blocker were administrated to evaluate the functional attenuation of mutated KCNJ5 channel in transfected HAC15 cells. The interaction between macrolides and KCNJ5 protein was evaluated via molecular docking and molecular dynamics simulation analysis. The immunohistochemistry analysis showed strong CYP11B2 immunoreactivity in the APA harboring KCNJ5 157-159delITE mutation. Whole-cell patch-clamp data revealed that mutated KCNJ5 157-159delITE channel exhibited loss of potassium ion selectivity. The mutant-transfected HAC15 cells increased the expression of CYP11B2 and aldosterone secretion, which was partially suppressed by clarithromycin and nifedipine but not roxithromycin treatment. The docking analysis and molecular dynamics simulation disclosed that roxithromycin had strong interaction with KCNJ5 L168R mutant channel but not with this KCNJ5 157-159delITE mutant channel. We showed comprehensive evaluations of the KCNJ5 157-159delITE mutation which revealed that it disrupted potassium channel selectivity and aggravated autonomous aldosterone production. We further demonstrated that macrolide antibiotics, roxithromycin, could not interfere the aberrant electrophysiological properties and gain-of-function aldosterone secretion induced by KCNJ5 157-159delITE mutation.

Download Full-text

Faculty Opinions recommendation of Molecular dynamics simulation analysis of membrane defects and pore propensity of hemifusion diaphragms.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717988413.793473345 ◽

2013 ◽

Author(s):

Jan Hoh

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Simulation Analysis ◽

Dynamics Simulation ◽

Membrane Defects

Download Full-text

Molecular dynamics simulation analysis of conessine against multi drug resistant Serratia marcescens

Infection Genetics and Evolution ◽

10.1016/j.meegid.2018.11.001 ◽

2019 ◽

Vol 67 ◽

pp. 101-111

Author(s):

Kalyani Dhusia ◽

Kalpana Raja ◽

Pierre Paul Michel Thomas ◽

Pramod K. Yadav ◽

Pramod W. Ramteke

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Serratia Marcescens ◽

Simulation Analysis ◽

Dynamics Simulation ◽

Drug Resistant

Download Full-text

Molecular Dynamics Simulation of Transmembrane Transport of Chloride Ions in Mutants of Channelrhodopsin

Biomolecules ◽

10.3390/biom9120852 ◽

2019 ◽

Vol 9 (12) ◽

pp. 852

Author(s):

Wenying Zhang ◽

Ting Yang ◽

Shuangyan Zhou ◽

Jie Cheng ◽

Shuai Yuan ◽

...

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Ion Channel ◽

Ion Selectivity ◽

Potential Of Mean Force ◽

Chloride Ions ◽

Dynamics Simulation ◽

Mutant Proteins ◽

Transmembrane Channel ◽

Anion Conduction

Channelrhodopsins (ChRs) are light-gated transmembrane cation channels which are widely used for optogenetic technology. Replacing glutamate located at the central gate of the ion channel with positively charged amino acid residues will reverse ion selectivity and allow anion conduction. The structures and properties of the ion channel, the transport of chloride, and potential of mean force (PMF) of the chimera protein (C1C2) and its mutants, EK-TC, ER-TC and iChloC, were investigated by molecular dynamics simulation. The results show that the five-fold mutation in E122Q-E129R-E140S-D195N-T198C (iChloC) increases the flexibility of the transmembrane channel protein better than the double mutations in EK-TC and ER-TC, and results in an expanded ion channel pore size and decreased steric resistance. The iChloC mutant was also found to have a higher affinity for chloride ions and, based on surface electrostatic potential analysis, provides a favorable electrostatic environment for anion conduction. The PMF free energy curves revealed that high affinity Cl− binding sites are generated near the central gate of the three mutant proteins. The energy barriers for the EK-TC and ER-TC were found to be much higher than that of iChloC. The results suggest that the transmembrane ion channel of iChloC protein is better at facilitating the capture and transport of chloride ions.

Download Full-text