Tomoaki Kinjo, Kenta Terai, Shoichiro Horita, Norimichi Nomura, Kenta Sumiyama, Kaori Togashi, So Iwata, Michiyuki Matsuda (2019) FRET-assisted photoactivation of flavoproteins for in vivo two-photon optogenetics., Nature methods, Volume 16, Number 10, pp. 1029-1036
Published in 2019 Oct (Electronic publication in Sept. 9, 2019, midnight )
(Abstract) Optical dimerizers have been developed to untangle signaling pathways, but they are of limited use in vivo, partly due to their inefficient activation under two-photon (2P) excitation. To overcome this problem, we developed Forster resonance energy transfer (FRET)-assisted photoactivation, or FRAPA. On 2P excitation, mTagBFP2 efficiently absorbs and transfers the energy to the chromophore of CRY2. Based on structure-guided engineering, a chimeric protein with 40% FRET efficiency was developed and named 2P-activatable CRY2, or 2paCRY2. 2paCRY2 was employed to develop a RAF1 activation system named 2paRAF. In three-dimensionally cultured cells expressing 2paRAF, extracellular signal-regulated kinase (ERK) was efficiently activated by 2P excitation at single-cell resolution. Photoactivation of ERK was also accomplished in the epidermal cells of 2paRAF-expressing mice. We further developed an mTFP1-fused LOV domain that exhibits efficient response to 2P excitation. Collectively, FRAPA will pave the way to single-cell optical control of signaling pathways in vivo.(MeSH Terms)