Of the many crucial functions of the ER, homeostasis of physiological calcium increase is critical for signaling. Plasma membrane (PM) injury causes a pathological calcium influx. Here, we show that the ER helps clear this surge in cytoplasmic calcium through an ER-resident calcium pump, SERCA, and a calcium-activated ion channel, Anoctamin 5 (ANO5). SERCA imports calcium into the ER, and ANO5 supports this by maintaining electroneutrality of the ER lumen through anion import. Preventing either of these transporter activities causes cytosolic calcium overload and disrupts PM repair (PMR). ANO5 deficit in limb girdle muscular dystrophy 2L (LGMD2L) patient cells compromises their cytosolic and ER calcium homeostasis. By generating a mouse model of LGMD2L, we find that PM injury causes cytosolic calcium overload and compromises the ability of ANO5-deficient myofibers to repair. Addressing calcium overload in ANO5-deficient myofibers enables them to repair, supporting the requirement of the ER in calcium homeostasis in injured cells and facilitating PMR.
Cellular and Molecular Physiology, School of Medicine, Yale University, New Haven, CT; Nanobiology Institute, Yale University, West Haven, CT; Molecular Biophysics and Biochemistry, Yale University, New Haven, CT; Saints-Pères Paris Institute for the Neurosciences (SPPIN), Université de Paris, Centre National de la Recherche Scientifique (CNRS) UMR 8003, Paris, France; Wu Tsai Institute, Yale University. Electronic address:
Synaptotagmin-1 (Syt1) is a major calcium sensor for rapid neurotransmitter release in neurons and hormone release in many neuroendocrine cells. It possesses two tandem cytosolic C2 domains that bind calcium, negatively charged phospholipids, and the neuronal SNARE complex. Calcium binding to Syt1 triggers exocytosis, but how this occurs is not well understood.
Activation of PLCβ enzymes by G and G proteins is a common mechanism to trigger cytosolic Ca increase. We and others reported that G inhibitor FR900358 (FR) can inhibit both and G - and, surprisingly, G -mediated intracellular Ca mobilization. Thus, the G -G -PLCβ-Ca signaling axis depends entirely on the presence of active G , which reasonably explained FR-inhibited G -induced Ca release.
Department of Integrated Applied Life Science, Integrated Graduate School of Medicine, Engineering, and Agricultural Sciences, University of Yamanashi, Yamanashi 400-0016, Japan.
Calcium release from the endoplasmic reticulum via sperm-derived phospholipase C zeta is crucial for oocyte activation during fertilization. Chloroquine (CQ) inhibits the increase in cytoplasmic calcium. This study investigated the effects of CQ on fertilization and oocyte activation.
Department of Medical BioSciences, Radboud University Medical Center, The Netherlands; Department of Medical Biochemistry, College of Medicine and Medical Sciences, Arabian Gulf University, Manama 329, Bahrain. Electronic address:
Messenger RNA is a highly promising biotherapeutic modality with great potential in preventive and therapeutic vaccination, and in the modulation of cellular function through transient expression of therapeutic proteins. However, for cellular delivery, mRNA requires packaging into delivery vehicles that mediate uptake and also shield the mRNA against degradation. Lipid-coated calcium phosphate (LCP) nanoparticles encapsulate the mRNA in a calcium phosphate core, which is coated by a bilayer of structural lipids, positively charged lipids and pegylated lipid to mediate cellular uptake and achieve colloidal stabilization.
As a member of the single-fluorophore genetically encoded calcium indicators (GECIs), jGCaMP7f is widely applied to investigate intracellular Ca concentrations. Here, we established an INS-jGCaMP7f knock-in H1 human embryonic stem cell (hESC) line by integrating jGCaMP7f gene into insulin locus via CRISPR/Cas9 system. The reporter cell line not only effectively labelled the insulin-producing cells induced from hESC, but also reflected the cytosolic change of Ca level in response to different stimuli.
