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Volume 3, Issue 4 (Suppl)
Nano Res Appl
ISSN: 2471-9838
November 07-08, 2017 Singapore
International Meeting on
Advanced Nanomaterials and Nanotechnology
Nanomaterials Meetings 2017
November 07-08, 2017
Page 49
Nano Res Appl 2017, 3:4
DOI: 10.21767/2471-9838-C1-006
Near-infrared optogenetic activation of channel rhodopsin expressed in living cells via upconverting
nanoparticles with target specificity
Kanchan Yadav
National Taiwan University, Taiwan
Optogenetics is an innovative technology now widely adopted by researchers in different fields of the biological sciences. However,
most proteins adopted in optogenetics are excited by ultra-violet or visible light that has a weak tissue penetration capability.
Upconverting nanoparticles (UCNPs), which transform near-infrared (NIR) light to short-wavelength emission, can help address
this issue. To improve optogenetic performance, we enhance the target selectivity for optogenetic controls by specifically conjugating
the UCNPs with light-sensitive proteins at a molecular level, which shortens the distance as well as enhances the efficiency of energy
transfer. We tagged V5 epitope to the extracellular N-terminal of channelrhodopsin-2 with a mCherry conjugated at the intracellular
C-terminal (V5-ChR2m) and then bound NeutrAvidin-functionalized UCNPs (NAv-UCNPs) to the V5-ChR2m via a biotinylated
antibody against V5. The results showed NAv-UCNPs bound to the plasma membranes of cells expressing V5-ChR2m, but not
ChR2m without the V5 epitope. Under NIR illumination, the NIR-upconverted blue illumination from UCNP induced an inward
cation current and elevated the intracellular Ca
2+
concentration in the live cells expressing V5-ChR2m bound with NAv-UCNPs. The
fluorescence resonance energy transfer (FRET) from the excited UCNP to the V5-ChR2m was confirmed by fluorescence lifetime
imaging measurements. Our results demonstrate that when membrane channelrhodopsin is specifically anchored by UCNPs in the
molecular level, the energy transfer via irradiance and FRET can greatly enhance the optogenetic performance.
kanchan.bitmesra@gmail.com