Fig. 5: Regulation of the flux from FPP toward β-carotene by using the developed switches.
From: Robust and flexible platform for directed evolution of yeast genetic switches
a Yeast strain used for the AND-gated control of carotenoid biosynthesis. The three plasmids expressing sTAs for use by the DAPG-ON2-1E, HSL-ON2-4F, and Tet-ONK8N, L131L switches were chromosomally integrated. The gene downstream of each synP (pphlO6, ptetO7, and pluxO5) was expressed only in the presence of corresponding inducer (DAPG, Dox, and HSL, respectively). b Orthogonal GFP expression control using Dox, DAPG, and HSL was measured by flow cytometry. c The pathway to β-carotene. FPP farnesyl diphosphate, GGPP geranylgeranyl diphosphate. d Constitutive and AND-gate-controlled β-carotene biosynthesis. Cell pellets of yeast strains (right panel) expressing (BTS1, crtYB, and crtI) under the control of constitutive promoter or synP (pphlO6, ptetO7, and pluxO5) in the combinations shown in left panel. These strains were inoculated into liquid medium with Inducers (Dox, DAPG, and HSL) in different combinations and incubated at 30°C for 24 hours. The concentrations of the inducers were as follows: DAPG (3 µM), HSL (3 µM), and Dox (10 µg/mL).
