Engineering of NEMO as calcium indicators with ultra-high dynamics and sensitivity

Li, J.; Shang, Z.; Chen, J.-H.; Gu, W.; Yao, L.; Yang, X.; Sun, X.; Wang, L.; Hou, T.; Wang, S.-Q.; Xing, D.; Gill, D. L.; Hou, L.; Zhou, Y.; Tang, A.-H.; Zhang, X.; Wang, Y.

doi:10.1101/2022.08.23.504677

bioRxiv · 10.1101/2022.08.23.504677

Engineering of NEMO as calcium indicators with ultra-high dynamics and sensitivity

Li, J.·Shang, Z.·Chen, J.-H.·Gu, W.·Yao, L.·Yang, X.·Sun, X.·Wang, L.·Hou, T.·Wang, S.-Q.·Xing, D.·Gill, D. L.·Hou, L.·Zhou, Y.·Tang, A.-H.·Zhang, X.·Wang, Y.

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Abstract

Genetically-encoded calcium indicators (GECI) are indispensable tools for real-time monitoring of intracellular calcium signals and cellular activities in living organisms. Current GECIs face the challenge of sub-optimal peak signal-to-baseline-ratio (SBR) with limited resolution for reporting subtle calcium transients. We report herein the development of a suite of calcium sensors, designated NEMO, with fast kinetics and wide dynamic ranges (>100-fold). NEMO indicators report Ca2+ transients with peak SBRs ~20-fold larger than the top-of-the-range GCaMP series. NEMO sensors further enable the quantification of absolution calcium concentration with ratiometric or photochromic imaging. Compared to GCaMPs, NEMOs could detect single action potentials in neurons with a peak SBR two times higher and a median peak SBR four times larger in vivo, thereby outperforming most existing state-of-the-art GECIs. Given their high sensitivity and resolution to report intracellular Ca2+ signals, NEMO sensors may find broad applications in monitoring neuronal activities and other Ca2+-modulated physiological processes in both mammals and plants.

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Li, J., Shang, Z., Chen, J.-H., Gu, W., Yao, L., Yang, X., Sun, X., Wang, L., Hou, T., Wang, S.-Q., Xing, D., Gill, D. L., Hou, L., Zhou, Y., Tang, A.-H., Zhang, X., Wang, Y.. 2022-08-23. Engineering of NEMO as calcium indicators with ultra-high dynamics and sensitivity. https://doi.org/10.1101/2022.08.23.504677

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