The Multiple Regulatory Relationship Between RNA-Chaperone Hfq and the Second Messenger c-di-GMP.

Yang Fu,Qi Tan,Zhou Li,Shan-Ho Chou,Li Zhu,Zhaoqing Yu,Wen Yin,Jin He,Xiaodong Shang

doi:10.3389/fmicb.2021.689619

Abstract

RNA chaperone protein Hfq is an important post-transcriptional regulator in bacteria, while c-di-GMP is a second messenger signaling molecule widely distributed in bacteria. Both factors have been found to play key roles in post-transcriptional regulation and signal transduction pathways, respectively. Intriguingly, the two factors show some common aspects in the regulation of certain physiological functions such as bacterial motility, biofilm formation, pathogenicity and so on. Therefore, there may be regulatory relationship between Hfq and c-di-GMP. For example, Hfq can directly regulate the activity of c-di-GMP metabolic enzymes or alter the c-di-GMP level through other systems, while c-di-GMP can indirectly enhance or inhibit the hfq gene expression through intermediate factors. In this article, after briefly introducing the Hfq and c-di-GMP regulatory systems, we will focus on the direct and indirect regulation reported between Hfq and c-di-GMP, aiming to compare and link the two regulatory systems to further study the complicated physiological and metabolic systems of bacteria, and to lay a solid foundation for drawing a more complete global regulatory network.

Highlights

Bacteria are single-celled organisms without complex tissues and systems, but they often live in highly variable physical and chemical environments in nature
Hfq directly regulates the expression of c-di-GMP metabolic enzymes and affects the concentration of intracellular c-diGMP, which is the most direct way for regulatory relationship between the two factors
The specific regulatory mechanism we speculate is as follows: When Hfq is present, it can bind to McaS to enhance its stability, which can tightly bind CsrA, leaving no free CsrA (CsrA is sequestered in this case) to block the ribosome binding sites of ydeH and ycdT mRNAs, resulting in successful translation of these two diguanylate cyclase (DGC) genes, and increasing intracellular c-di-GMP concentration

Summary

Introduction

Bacteria are single-celled organisms without complex tissues and systems, but they often live in highly variable physical and chemical environments in nature. Hfq directly regulates the expression of c-di-GMP metabolic enzymes and affects the concentration of intracellular c-diGMP, which is the most direct way for regulatory relationship between the two factors.

Results

Conclusion