Ion channels are interesting molecules since they mediate not only uterine contraction but also uterine relaxation. We have examined the expression, function, and correlation between the large conductance calcium-activated potassium (BKCa) channel, beta2 adrenoceptor (AR), and long-lasting (L) type calcium (Ca2+) channel. These are the main channels and receptor that are involved in the uterine contraction/ relaxation process. Our evidence has shown that BKCa channel is closely correlated with beta2 AR in mediating uterine relaxation. Both proteins are situated in close proximity on the plasma membrane of human myometrium and are downregulated approximately 50% after the onset of labor. Interestingly, L type Ca2+ channel, which involves in the contraction pathway, seems to be in the same compartmentation as BKCa channel/ beta2 AR macromolecular complex. Further studies are now being conducted to identify the signaling complex components that could potentially be a target for new tocolytic agents.
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Front Neurosci
December 2024
National Key Laboratory of Space Medicine, China Astronaut Research and Training Center, Beijing, China.
Hibernation, an adaptive mechanism to extreme environmental conditions, is prevalent among mammals. Its main characteristics include reduced body temperature and metabolic rate. However, the mechanisms by which hibernating animals re-enter deep sleep during the euthermic phase to sustain hibernation remain poorly understood.
View Article and Find Full Text PDFNative ion channels play key roles in biological systems, and engineered versions are widely used as chemogenetic tools and in sensing devices . Protein design has been harnessed to generate pore-containing transmembrane proteins, but the capability to design ion selectivity based on the interactions between ions and selectivity filter residues, a crucial feature of native ion channels , has been constrained by the lack of methods to place the metal-coordinating residues with atomic-level precision. Here we describe a bottom-up RFdiffusion-based approach to construct Ca channels from defined selectivity filter residue geometries, and use this approach to design symmetric oligomeric channels with Ca selectivity filters having different coordination numbers and different geometries at the entrance of a wide pore buttressed by multiple transmembrane helices.
View Article and Find Full Text PDFIn the human heart, the binding of cyclic adenosine monophosphate (cAMP), a second messenger, to hyperpolarization and cyclic nucleotide-gated (HCN) regulates the automaticity of pacemaker cells. Recent single-molecule binding studies show that cAMP bound to each subunit of purified tetrameric HCN channels independently, in contrast to findings in cells. To explore the lipid membrane's role in cAMP regulation, we reconstituted purified human HCN channels in various lipid nanodiscs and resolved single molecule ligand-binding dynamics.
View Article and Find Full Text PDFBackground: Juxtaglomerular (JG) cells are sensors that control blood pressure and fluid-electrolyte homeostasis. In response to a decrease in perfusion pressure or changes in the composition and/or volume of the extracellular fluid, JG cells release renin, which initiates an enzymatic cascade that culminates in the production of angiotensin II (Ang II), a potent vasoconstrictor that restores blood pressure and fluid homeostasis. In turn, Ang II exerts a negative feedback on renin release, thus preventing excess circulating renin and the development of hypertension.
View Article and Find Full Text PDFSmall
January 2025
National and Local Joint Engineering Laboratory for Lithium-ion Batteries and Materials Preparation Technology, Key Laboratory of Advanced Battery Materials of Yunnan Province, Faculty of Metallurgical and Energy Engineering, Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, 650093, China.
Owing to its abundant manganese source, high operating voltage, and good ionic diffusivity attributed to its 3D Li-ion diffusion channels. Spinel LiMnO is considered a promising low-cost positive electrode material in the context of reducing scarce elements such as cobalt and nickel from advanced lithium-ion batteries. However, the rapid capacity degradation and inadequate rate capabilities induced by the Jahn-Teller distortion and the manganese dissolution have limited the large-scale adoption of spinel LiMnO for decades.
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