Fig. 1: A genetic screen identifies positive regulators of photo sensing.
a Schematic of BphP-AlgB photo-sensing signaling cascade in P. aeruginosa. Light (denoted by “sun” symbol) stimulates the BphP kinase (green) to auto-phosphorylate and subsequently transfer the phosphoryl group to AlgB (brown) to activate AlgB. AlgB~P activates transcription of genes required for repression of group behaviors such as biofilm formation and virulence factor production. KinB (gray) acts as a phosphatase to antagonize AlgB. A “P” in a circle denotes addition or removal of a phosphate moiety. Arrow indicates activation, and T-bar indicates inhibition. b Colony biofilms under dark (denoted by “black crescent” symbol) and far-red (denoted by “red bulb” symbol) for WT, bphPSTOP, ΔalgB. Scale bar, 5 mm. Representative images shown of 3 independent experiments. c Quantification of lecA-lux activity in WT and mutant backgrounds under dark (black bars) and far-red light (red bars) conditions. d Quantification of lecA-lux activity for Tn5-candidates. e Quantification of lecA-lux activity in WT and mutant backgrounds under ambient light conditions. c–e Error bars represent SEM of three biological replicates (n = 3). Statistical significance was determined using two-way ANOVA for 1c and unpaired, two-tailed Welch’s t tests for pairwise comparisons for 1d-e in GraphPad Prism software (version 10.6.0). **** P < 0.0001, ** P < 0.005, * P < 0.05, ns not significant. Significant P-values were calculated as (left to right): For 1c 0.0010, for 1 d 0.0064, 0.0017, 0.0058, 0.0161, 0.0284, 0.0415, 0.0367, for 1e 0.0025, 0.0022, 0.0025, 0.0022.
