Monitoring NAD(H) and NADP(H) dynamics during organismal development with genetically encoded fluorescent biosensors

Cell Regeneration

Table 1 Genetically encoded fluorescent sensors for NAD(H) and NADP(H)

	Species sensed	Affinity	Dynamic Changes	Sensor type	pH sensitivity	Brightness in cells	Reference
Frex	NADH	\({\mathrm K}_{\mathrm{NADH}}:\;\sim3.7\;\mathrm{\upmu{M}}\)	800%	Ratiometric	Sensitive	Weak^f	(Zhao et al. 2011)
LigA-cpVenus	NAD⁺	\({\mathrm{K}}_{\mathrm{NAD}^+}:\;\sim\:65\:\mathrm{\upmu M}\)	100%	Ratiometric	Sensitive	N.D.	(Cambronne et al. 2016)
FiNad	NAD⁺/AXP^a	\({\mathrm{K}}_{\mathrm{NAD}^+}:\;\sim1300\;\mathrm{\upmu M}^\mathrm{b}\)	700%	Ratiometric	Sensitive	N.D.	(Zou et al. 2020)
Peredox	NADH/NAD⁺	\(\mathrm{K}_{\mathrm{NAD}^+/\mathrm{NADH}}:\;\sim330\)	150%	Intensiometric	Resistant	Moderate^f	(Hung et al. 2011)
RexYFP	NADH/NAD⁺	\({\mathrm{K}}_\mathrm{NADH}:\;\sim0.18\;\mathrm{\upmu M}\)	50%	Intensiometric	Sensitive	N.D.	(Bilan et al. 2014)
SoNar	NADH/NAD⁺	\({\mathrm{K}}_{\mathrm{NAD}^+/\mathrm{NADH}}:\;\sim40\)	1500%	Ratiometric	Resistant^d	Strong^f	(Zhao et al. 2015)
Apollo-NADP⁺	NADP⁺	\({\mathrm{K}}_{\mathrm{NADP}^+}:\;0.1-20\;\mathrm{\upmu M}\)	15-20%	Ratiometric	Resistant^e	N.D.	(Cameron et al. 2016)
NADPsor	NADP⁺	\({\mathrm{K}}_{\mathrm{NADP}^+}:\;\sim2000\;\mathrm{\upmu M}\)	30%	Ratiometric	Resistant	N.D.	(Zhao et al. 2016a)
iNap1-4	NADPH	\({\mathrm{K}}_\mathrm{NADPH}:\;\sim2-120\;\mathrm{\upmu M}^\mathrm{c}\)	500-1000%	Ratiometric	Resistant^d	Strong^f	(Tao et al. 2017)

N.D., not determined
^aAXP denotes ADP and ATP
^bIt is measured in the presence of 1 mM AXP
^cNADPH sensors iNap 1–4 have different affinities with K_d values of ∼2.0 μM, ∼6.0 μM, ∼25 μM, and ∼120 μM, respectively
^dSoNar’s and iNap’s fluorescence excited at 420 nm, dynamic range, \({\mathrm{K}}_{\mathrm{NAD}^+/\mathrm{NADH}}\) and K_NADPH are pH resistant
^eVenus-tagged Apollo-NADP⁺ sensor was pH resistant in the pH range of 7.25–8, but showed a progressively decreasing dynamic range below pH 7.25
^fThe data come from side-by-side comparison studies (Tao et al. 2017; Zhao et al. 2015)