Photoswitchable GECI
Posted in Tips
Many red fluorescent proteins go through a green fluorescent stage prior to becoming fully folded into their mature red fluorescent state. In fact, some proteins can be photoswitched in and/or out of their mature red state, e.g., Dendra2, EosFP, and Kaede.
Given this protein engineering know-how, perhaps it was just a matter of time before someone made a photoswitchable genetically encoded calcium indicator (GECI). The excellent OpenOptogenetics blog has a post up on the recent report from Robert Campbell and Takeharu Nagai labs (two GECI heavyweights). (link to article)
If anyone is considering taking this in vivo or acute slice, I’d suggest reading Yamada and Mikoshiba 2012. I recently tested RGECO and came to similar conclusions. The signal difference is much reduced compared to the published results in HeLa and cultured cells.