Role of a short LOV protein in blue light- and singlet oxygen-dependent gene regulation in Rhodobacter sphaeroides

The facultatively photosynthetic bacterium Rhodobacter sphaeroides harbors an unusual LOV (light, oxygen, voltage) domain protein, RsLOV. While showing a characteristic photocycle, the protein misses a C - terminal output domain, similar to PpSB2 in Pseudomonas putida. Oxygen tension and light quantity are the two main responsible factors controlling the expression of photosynthesis genes in Rhodobacter sphaeroides. Two photoreceptor proteins are known to be involved in this regulation: the intensively studied AppA protein and the more recently identified cryptochrome-like protein CryB. Here we show by transcriptome and physiological studies that RsLOV is also involved in the regulation of photosynthetic gene expression. Our data further hint to a connection between RsLOV and the carbon hydrate metabolism, chemotaxis, as well as to the cellular response to photooxidative stress. RsLOV does not only affect blue light dependent gene expression but also redox-dependent regulation. This SuperSeries is composed of the following subset Series: GSE33194: R. sphaeroides Δlov vs. R. sphaeroides 2.4.1 (microarobic conditions) GSE33259: R. sphaeroides Δlov vs. R. sphaeroides 2.4.1 (blue light, semiaerobic conditions) GSE33260: R. sphaeroides Δlov vs. R. sphaeroides 2.4.1 (singlet oxygen stress, aerobic conditions)