An oscillatory increase in pancreatic beta cell cytoplasmic free Ca2+ concentration, [Ca2+]i, is a key feature in glucose-induced insulin release. The role of the voltage-gated Ca2+ channel beta3 subunit in the molecular regulation of these [Ca2+]i oscillations has now been clarified by using beta3 subunit-deficient beta cells. beta3 knockout mice showed a more efficient glucose homeostasis compared to wild-type mice due to increased glucose-stimulated insulin secretion. This resulted from an increased glucose-induced [Ca2+]i oscillation frequency in beta cells lacking the beta3 subunit, an effect accounted for by enhanced formation of inositol 1,4,5-trisphosphate (InsP3) and increased Ca2+ mobilization from intracellular stores. Hence, the beta3 subunit negatively modulated InsP3-induced Ca2+ release, which is not paralleled by any effect on the voltage-gated L type Ca2+ channel. Since the increase in insulin release was manifested only at high glucose concentrations, blocking the beta3 subunit in the beta cell may constitute the basis for a novel diabetes therapy.
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http://dx.doi.org/10.1016/j.cell.2004.09.033 | DOI Listing |
Prog Biophys Mol Biol
January 2025
Center for Cancer Prevention and Treatment, Second Hospital of Shandong University, Jinan, Shandong, China. Electronic address:
Gastric cancer (GC) remains a significant global health burden due to its high aggressiveness, early metastasis, and poor prognosis. Despite advances in chemotherapy and targeted therapies, drug resistance remains a major obstacle to improving patient outcomes. Integrins, a family of transmembrane receptors, play a pivotal role in mediating tumor growth, invasion, and drug resistance by interacting with the tumor microenvironment (TME) and regulating signaling pathways such as Wnt/β-catenin, FAK, and MAPK.
View Article and Find Full Text PDFAnesth Analg
November 2024
From the Department of Anesthesia Critical Care & Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts.
Background: R-Glabridin is a major flavonoid of licorice (Glycyrrhiza glabra) root and known to modulate GABAA receptors, which are targets of many clinical hypnotics. However, R-glabridin hypnotic activity has not been reported in animals.
Methods: Inverted photomotor responses (IPMRs) were used to assess the hypnotic effects of natural R-glabridin and synthetic R/S-glabridin in wild-type zebrafish larvae and transgenic larvae lacking functional GABAA receptor β3 subunits (β30/0).
J Mol Cell Cardiol
January 2025
Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK. Electronic address:
Introduction: Brugada Syndrome (BrS) is an inherited arrhythmia syndrome characterised by ST-segment elevation in the right precordial ECG leads and is associated with an increased risk of sudden cardiac death. We identify and characterise a novel SCN3B variant encoding the regulatory β3-subunit of the cardiac voltage-gated sodium channel, Na1.5.
View Article and Find Full Text PDFStructure
December 2024
Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA; Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, USA; Department of Biochemistry, University of Utah, Salt Lake City, UT, USA; Department of Molecular Pharmaceutics, University of Utah, Salt Lake City, UT, USA. Electronic address:
As major adhesion receptors, integrins transmit biochemical and mechanical signals across the plasma membrane. These functions are regulated by transitions between bent and extended conformations and modulated by force. To understand how force on integrins mediates cellular mechanosensing, we compared two highly homologous integrins, αβ and αβ.
View Article and Find Full Text PDFJ Gen Physiol
January 2025
Department of Biochemistry, Hopkins Building, University of Cambridge, Cambridge, UK.
Voltage-gated sodium channel α-subunits (NaV1.1-1.9) initiate and propagate action potentials in neurons and myocytes.
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