Engineering and diverse biomedical applications of bacteriophytochromes

Bacteriophytochromes (BphPs) are a class of widely distributed biliverdin (BV) bound bacterial photoreceptor proteins that can respond to red or far-red light. BphPs have been employed as photoresponsive module in red/far-red light control of physiological processes, and the photoresponsive properties of BphPs can be modulated through various engineering strategies, such as addition, deletion and substitution. Therefore, BphPs have been the focus of a variety of researches. Recently, progress has been made in both the engineering of BphPs and their subsequent applications across diverse biomedical fields, paving the way for their use as versatile biotechnological tools. However, there has not yet been a comprehensive review that systematically summarizes the recent advancements of engineering and diverse biomedical applications of BphPs. Here, the structural characteristics and photochemical properties of BphPs, the advancements of engineering approaches and various biomedical applications of BphPs, the comparative analyses of the engineering and applications of phytochromes from bacteria and plants, as well as the research challenges and future research directions of this field are systematically summarized and analyzed, aiming to provide a basis for further in-depth research and the expansion of the application fields of BphPs.