Highly dynamic and sensitive NEMOer calcium indicators for imaging ER calcium signals in excitable cells

作者：Wenjia Gu, Jiahui Chen, Yiyin Zhang, Zhirong Wang, JIA LIN LI, Sijia Wang, Sijia Wang, Hanhan Zhang, Amin Jiang, Jiaxuan Zhang, Jiaxuan Zhang, XU Ze, Panpan Liu, Chao Xi, Tingting Hou, Donald L. Gill, Dong Li, Yu Mu, Ai‐Hui Tang, Youjun Wang, Ai‐Hui Tang, Youjun Wang · 发表于：Nature Communications · 年份：2025 · DOI：10.1038/s41467-025-58705-6 · 被引用次数：9 · 研究领域：Neuroscience and Neuropharmacology Research、Neuroscience and Neural Engineering、Ion channel regulation and function

The Endoplasmic/sarcoplasmic reticulum (ER/SR) is central to calcium (Ca2+) signaling, yet current genetically encoded Ca2+ indicators (GECIs) cannot detect elementary Ca2+ release events from ER/SR, particularly in muscle cells. Here, we report NEMOer, a set of organellar GECIs, to efficiently capture ER Ca2+ dynamics with increased sensitivity and responsiveness. NEMOer indicators exhibit dynamic ranges an order of magnitude larger than G-CEPIA1er, enabling 2.7-fold more sensitive detection of Ca2+ transients in both non-excitable and excitable cells. The ratiometric version further allows super-resolution monitoring of local ER Ca2+ homeostasis and dynamics. Notably, NEMOer-f enabled the inaugural detection of Ca2+ blinks, elementary Ca2+ releasing signals from the SR of cardiomyocytes, as well as in vivo spontaneous SR Ca2+ releases in zebrafish. In summary, the highly dynamic NEMOer sensors expand the repertoire of organellar Ca2+ sensors that allow real-time monitoring of intricate Ca2+ dynamics and homeostasis in live cells with high spatiotemporal resolution. The endoplasmic/sarcoplasmic reticulum (ER/SR) plays a crucial role in calcium signaling, but there are few methods capable of efficiently capturing ER/SR Ca2+ dynamics. Here authors develop a set of genetically encoded indicators enabling ratiometric super-resolution imaging and detection of elementary Ca2+ release in cardiomyocytes.