Two pore channels are lysosomal cation channels with crucial roles in tumor angiogenesis and viral release from endosomes. Inhibition of the two-pore channel 2 (TPC2) has emerged as potential therapeutic strategy for the treatment of cancers and viral infections, including Ebola and COVID-19. Here, we demonstrate that antagonist SG-094, a synthetic analog of the Chinese alkaloid medicine tetrandrine with increased potency and reduced toxicity, induces asymmetrical structural changes leading to a single binding pocket at only one intersubunit interface within the asymmetrical dimer. Supported by functional characterization of mutants by Ca imaging and patch clamp experiments, we identify key residues in S1 and S4 involved in compound binding to the voltage sensing domain II. SG-094 arrests IIS4 in a downward shifted state which prevents pore opening via the IIS4/S5 linker, hence resembling gating modifiers of canonical VGICs. These findings may guide the rational development of new therapeutics antagonizing TPC2 activity.
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http://dx.doi.org/10.1016/j.str.2024.05.005 | DOI Listing |
Front Pharmacol
January 2025
IDiBE-Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche, Universidad Miguel Hernández, Elche, Spain.
The Selectivity Filter (SF) in tetrameric K channels, has a highly conserved sequence, TVGYG, at the extracellular entry to the channel pore region. There, the backbone carbonyl oxygens from the SF residues, create a stack of K binding sites where dehydrated K binds to induce a conductive conformation of the SF. This increases intersubunit interactions and confers a higher stability to the channel against thermal denaturation.
View Article and Find Full Text PDFPlant Cell Environ
January 2025
Department of Biotechnology, Central University of Haryana, Mahendergarh, Haryana, India.
Tonoplast intrinsic proteins (TIPs) are the channel-forming proteins predominantly found in the tonoplast of plant cells. Despite the identification of TIPs in numerous plant species, very less is known about the precise role of different TIP subgroups. In the present study, two genes belonging to the TIP3 subgroup were studied to understand tissue-specific role and solute transport activity.
View Article and Find Full Text PDFUnlabelled: Exposure to loud and/or prolonged noise damages cochlear hair cells and triggers downstream changes in synaptic and electrical activity in multiple brain regions, resulting in hearing loss and altered speech comprehension. It remains unclear however whether or not noise exposure also compromises the cochlear efferent system, a feedback pathway in the brain that fine-tunes hearing sensitivity in the cochlea. We examined the effects of noise-induced hearing loss on the spontaneous action potential (AP) firing pattern in mouse lateral olivocochlear (LOC) neurons.
View Article and Find Full Text PDFLangmuir
January 2025
College of Physical Science and Technology, Yangzhou University, Yangzhou 225002, China.
Porous nanomaterials have shown great promise in many desalination applications. Zeolite nanotubes, featuring abundant but inhomogeneous nanopores on their surface, have been recently synthesized in experiments; however, their capacity for desalination is not yet understood. In this work, we use molecular dynamics simulations to investigate the capability of assembled zeolite nanotube membranes to perform in desalination applications due to their inherent multiscale porous properties.
View Article and Find Full Text PDFNat Chem Biol
January 2025
Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China.
Voltage-gated ion channels (VGICs) are crucial targets for neuropsychiatric therapeutics owing to their role in controlling neuronal excitability and the established link between their dysfunction and neurological diseases, highlighting the importance of identifying modulators with distinct mechanisms. Here we report two small-molecule modulators with the same chemical scaffold, Ebio2 and Ebio3, targeting a potassium channel KCNQ2, with opposite effects: Ebio2 acts as a potent activator, whereas Ebio3 serves as a potent and selective inhibitor. Guided by cryogenic electron microscopy, patch-clamp recordings and molecular dynamics simulations, we reveal that Ebio3 attaches to the outside of the inner gate, employing a unique non-blocking inhibitory mechanism that directly squeezes the S6 pore helix to inactivate the KCNQ2 channel.
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