Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology, Warsaw, Poland.
Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology, Warsaw, Poland;
Acta Neurobiol Exp (Wars). 2021;81(4):307-313.
Store‑operated calcium entry (SOCE) is important for refilling endoplasmic reticulum (ER) Ca2+ stores and Ca2+ signaling. Extracellular Ca2+ is conducted by highly Ca2+‑selective Orai channels that are activated by stromal interaction molecule proteins (STIMs), which are sensitive ER Ca2+ sensors. We found an approximately five‑fold increase in annexin A3a (anxa3a) expression levels in stim2b knockout zebrafish. The present study investigated whether annexin A3 protein is involved in SOCE. We used Ca2+ imaging and electrophysiological recordings to determine the effect of annexin A2, A3, and A6 overexpression on SOCE and Orai-dependent Ca2+ currents (ICRAC) in cultured cells. Annexin A3 increased SOCE amplitude and potentiated Ca2+ ICRAC currents. These results suggest that annexin A3 is a positive modulator of SOCE.
钙库操纵性钙内流（SOCE）对于内质网（ER）Ca2+ 储存和 Ca2+ 信号转导非常重要。细胞外 Ca2+ 通过高度 Ca2+ 选择性的 Orai 通道进行传导，该通道由基质相互作用分子蛋白（STIMs）激活，而 STIMs 是 ER Ca2+ 传感器。我们发现，在 stim2b 基因敲除斑马鱼中， annexin A3a（anxa3a）的表达水平增加了约五倍。本研究探讨了 annexin A3 蛋白是否参与 SOCE。我们使用 Ca2+ 成像和电生理记录来确定 annexin A2、A3 和 A6 过表达对培养细胞中 SOCE 和 Orai 依赖性 Ca2+ 电流（ICRAC）的影响。Annexin A3 增加了 SOCE 的幅度并增强了 Ca2+ ICRAC 电流。这些结果表明 annexin A3 是 SOCE 的正调节剂。
