Quantitative proteomics reveals the complex regulatory networks of LTTR-type regulators in pleiotropic functions of Aeromonas hydrophila

Lishan Zhang; Yuying Fu; Qiaozhen Xu; Xin Chen; Yuyue Xie; Binghui Zhang; Xiangmin Lin

doi:10.1016/j.ijbiomac.2024.132315

Quantitative proteomics reveals the complex regulatory networks of LTTR-type regulators in pleiotropic functions of Aeromonas hydrophila

Int J Biol Macromol. 2024 May 11;270(Pt 1):132315. doi: 10.1016/j.ijbiomac.2024.132315. Online ahead of print.

Authors

Lishan Zhang¹, Yuying Fu², Qiaozhen Xu¹, Xin Chen¹, Yuyue Xie¹, Binghui Zhang³, Xiangmin Lin⁴

Affiliations

¹ College of JunCao Science and Ecology, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Crop Ecology and Molecular Physiology, Fujian Agriculture and Forestry University, Fujian Province University, Fuzhou 350002, China; Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
² School of Safety and Environment, Fujian Chuanzheng Communications College, Fuzhou, Fujian Province 350007, China.
³ College of JunCao Science and Ecology, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Institute of Tobacco Science, Fujian Provincial Tobacco Company, Fuzhou 350003, China.
⁴ College of JunCao Science and Ecology, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Crop Ecology and Molecular Physiology, Fujian Agriculture and Forestry University, Fujian Province University, Fuzhou 350002, China; Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou 350002, China. Electronic address: xiangmin@fafu.edu.cn.

PMID: 38740149
DOI: 10.1016/j.ijbiomac.2024.132315

Abstract

LysR-type transcriptional regulators (LTTRs) are ubiquitously distributed and abundant transcriptional regulators in prokaryotes, playing pivotal roles in diverse physiological processes. Nonetheless, despite their prevalence, the intricate functionalities and physiological implications of this protein family remain incompletely elucidated. In this study, we employed a comprehensive approach to deepen our understanding of LTTRs by generating a collection of 20 LTTR gene-deletion strains in Aeromonas hydrophila, accounting for 42.6 % of the predicted total LTTR repertoire, and subjected them to meticulous assessment of their physiological phenotypes. Leveraging quantitative proteomics, we conducted a comparative analysis of protein expression variations between six representative mutants and the wild-type strain. Subsequent bioinformatics analysis unveiled the involvement of these LTTRs in modulating a wide array of biological processes, notably including two-component regulatory systems (TCSs) and intracellular central metabolism. Moreover, employing subsequent microbiological methodologies, we experimentally verified the direct involvement of at least six LTTRs in the regulation of galactose metabolism. Importantly, through ELISA and competitive ELISA assays, we demonstrated the competitive binding capabilities of these LTTRs with the promoter of the α-galactosidase gene AHA_1897 and identified that four LTTRs (XapR, YidZ, YeeY, and AHA_1805) do not engage in competitive binding with other LTTRs. Overall, our comprehensive findings not only provide fundamental insights into the regulatory mechanisms governing crucial physiological functions of bacteria through LTTR family proteins but also uncover an intricate and interactive regulatory network mediated by LTTRs.

Keywords: Aeromonas hydrophila; LTTRs; Quantitative proteomics; Regulatory network; Transcription regulator.