Fig. 4

Transcriptional regulation changes carotenoid production. a Yeast MVA pathway coupled to carotenoid production. Red triangles (repression with PCP-Mxi1) and green triangles (activation with MCP-VPR) illustrate the orientation of transcriptional regulation on selected promoters. pHMG1 and pERG20 were targeted for regulation in up to two sites simultaneously, and pERG9 was either activated or repressed in different modules. b Nine strains (Sc-128 to Sc-136) are shown with single scRNAs targeting indicated promoters for regulation. Triangles indicate repression or activation as in a. Representative phenotypes including control (Sc-124) are presented next to respective constructs. c Left Individual scRNAs presented in b were multiplexed into three different designs. Triangles indicate reprogramming as in a. Right Quantification of β-carotene titers for each strain is presented. Values are shown as mean ± S.D. from three (n = 3) biological replicate experiments (*p < 0.01). d Growth assay depicting dry cell weight (DCW) per liter (g/L) as function of time for strains shown in c expressing multiplex scRNA designs for regulating carotenoid production. Blue Sc-124. Purple Sc-125. Green Sc-126. Red Sc-127. Presented data are averages of three biological replicates