Substantial progress has been made in the past several years in establishing the stoichiometries of STIM and Orai proteins and understanding their influence on store-operated calcium entry. Depletion of ER Ca triggers STIM1 to accumulate at ER-plasma membrane junctions where it binds and opens Ca release-activated Ca (CRAC) channels. STIM1 is a dimer, and release of Ca from its two luminal domains is reported to promote their association as well as drive formation of higher-order STIM1 oligomers. The CRAC channel, originally thought to be tetrameric, is now considered to be a hexamer of Orai1 subunits based on crystallographic and electrophysiological studies. STIM1 binding activates CRAC channels in a highly nonlinear way, such that all six Orai1 binding sites must be occupied to account for the activation and signature properties of native channels. The structural basis of STIM1 engagement with the channel is currently unclear, with evidence suggesting that STIM1 dimers bind to individual or pairs of Orai1 subunits. This review examines evidence that has led to points of consensus and debate about STIM1 and Orai1 stoichiometries, and explains the importance of STIM-Orai complex stoichiometry for the regulation of store-operated calcium entry.
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http://dx.doi.org/10.1016/j.ceca.2019.02.002 | DOI Listing |
Cardiovasc Drugs Ther
January 2025
Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China.
Purpose: Doxorubicin (Dox) is a classic anthracycline chemotherapy drug with cause cumulative and dose-dependent cardiotoxicity. This study aimed to investigate the potential role and molecular mechanism of phenylacetylglutamine (PAGln), a novel gut microbiota metabolite, in Dox-induced cardiotoxicity (DIC).
Methods: DIC models were established in vivo and in vitro, and a series of experiments were performed to verify the cardioprotective effect of PAGln.
Sci Rep
January 2025
Laboratory of Biomedical Imaging and Data Analysis, Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, Khlopina St. 11, St. Petersburg, Russia, 194021.
One of the mechanisms of calcium signalling in neurons is store-operated calcium entry (SOCE), which is activated when the calcium concentration in the smooth endoplasmic reticulum (ER) decreases and its protein-calcium sensor STIM (stromal interacting molecule) relocate to the endoplasmic reticulum and plasma membrane junctions, forms clusters and induces calcium entry. In electrically non-excitable cells, STIM1 is coupled with the positive end of a tubulin microtubule through interaction with EB1 (end-binding) protein, which controls its oligomerization, SOCE and participates in ER movement. STIM2 homologue, which is specific for mature hippocampal dendritic spines, is known to interact with EB3 protein, however, not much is known about the role of this interaction in STIM2 clustering or ER trafficking in neurons.
View Article and Find Full Text PDFBMC Med
January 2025
Physiological Institute, University of Regensburg, University Street 31, 93053, Regensburg, Germany.
Background: Dystonia is a common neurological hyperkinetic movement disorder that can be caused by mutations in anoctamin 3 (ANO3, TMEM16C), a phospholipid scramblase and ion channel. We previously reported patients that were heterozygous for the ANO3 variants S651N, V561L, A599D and S651N, which cause dystonia by unknown mechanisms.
Methods: We applied electrophysiology, Ca measurements and cell biological methods to analyze the molecular mechanisms that lead to aberrant intracellular Ca signals and defective activation of K channels in patients heterozygous for the ANO3 variants.
Int Immunopharmacol
January 2025
Department of Bone Metabolism, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Research Center of Dental Materials and Oral Tissue Regeneration & Shandong Provincial Clinical Research Center for Oral Diseases, No.44-1 Wenhua Road West, 250012, Jinan, Shandong, China; Center of Osteoporosis and Bone Mineral Research, Shandong University, Jinan, China; School of Clinical Medicine, Jining Medical University, Jining, China; Institute of Oral Basic Research, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University. Electronic address:
Diabetes exacerbates the occurrence and severity of periodontitis, the pathogenesis of diabetic periodontitis (DPD) is influenced by the delayed resolution of inflammation. Eldecalcitol (ED-71) has shown promise in preventing bone loss in DPD. We herein aimed to investigate the role of ED-71 in the inflammatory regression phase of DPD and elucidate the underlying mechanisms.
View Article and Find Full Text PDFBiol Pharm Bull
December 2024
Laboratory of Clinical and Translational Physiology, Kyoto Pharmaceutical University.
Mucociliary clearance (MCC) is a host defense mechanism of the respiratory system. Beating cilia plays a crucial role in the MCC process and ciliary beat frequency (CBF) is activated by several factors including elevations of the intracellular cAMP concentration ([cAMP]), intracellular Ca concentration ([Ca]), and intracellular pH (pH). In this study, we investigated whether an artichoke-extracted component cynaropicrin could be a beneficial compound for improving MCC.
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