Publications by authors named "Zhengguo He"

The covalently attached cofactor biotin plays pivotal roles in central metabolism. The top-priority ESKAPE-type pathogens, and , constitute a public health challenge of global concern. Despite the fact that the late step of biotin synthesis is a validated anti-ESKAPE drug target, the primary stage remains fragmentarily understood.

View Article and Find Full Text PDF

Insertion sequences (ISs) exist widely in bacterial genomes, but their roles in the evolution of bacterial antiphage defense remain to be clarified. Here, we report that, under the pressure of phage infection, the IS transposition of into the gene can occur at high frequencies, which endows the mutant mycobacterium with a broad-spectrum antiphage ability. Lsr2 functions as a negative regulator and directly silences expression of a gene island composed of 11 lipid metabolism-related genes.

View Article and Find Full Text PDF

Zinc excess is toxic to bacteria and, thus, represents an important innate defense mechanism of host cells, especially against mycobacterial infections. However, the signaling pathway triggered by zinc excess and its relationship with iron homeostasis remain poorly understood in mycobacteria. Here, we characterize a novel Zur-IdeR-iron homeostasis signaling pathway that modulates the growth of under zinc toxicity.

View Article and Find Full Text PDF

In eukaryotic cells, serine/threonine protein kinases (StpKs) play important roles in limiting viral infections. StpKs are commonly activated upon infections, inhibiting the expression of genes central for viral replication. Here, we report that a eukaryotic-like StpK7 encoded by MSMEG_1200 in M.

View Article and Find Full Text PDF

Linear (Met1-linked) ubiquitination is involved inflammatory and innate immune signaling. Previous studies have characterized enzymes regulating the addition and removal of this modification in mammalian systems. However, only a few plant-derived deubiquitinases targeting Met1-linked ubiquitin chains have been reported and their mechanism of action remains elusive.

View Article and Find Full Text PDF

The normal operation of the endoplasmic reticulum (ER) is critical for cells and organisms. However, ER stress, caused by imbalanced protein folding, occurs frequently, which perturbs the function of the ER and even results in cell apoptosis eventually. Many insults can induce ER stress; pathogen infection is one of them.

View Article and Find Full Text PDF

Zinc is a microelement essential for the growth of almost all organisms, but it is toxic at high concentrations and represents an antimicrobial strategy for macrophages. Mycobacterium tuberculosis and Mycobacterium bovis are two well-known intracellular pathogens with strong environmental adaptability, including zinc toxicity. However, the signaling pathway and molecular mechanisms on sensing and resistance to zinc toxicity remains unclear in mycobacteria.

View Article and Find Full Text PDF

During infection, intracellular pathogens inevitably face the pressure of hypoxia. Mycobacterium tuberculosis and Mycobacterium bovis represent two typical intracellular bacteria, but the signalling pathway of their adaptation to hypoxia remains unclear. Here, we report a new mechanism of the hypoxic adaptation in M.

View Article and Find Full Text PDF

In view of the high malignancy and poor prognosis of human epidermal growth factor receptor 2 (HER2)-positive breast cancer, we analyzed the RNA expression profiles of HER2-positive breast cancer samples to identify the new prognostic biomarkers. The linear fitting method was used to identify the differentially expressed RNAs from the HER2-positive breast cancer RNA expression profiles in the Cancer Genome Atlas (TCGA). Then, a series of methods including univariate Cox, Kaplan-Meier, and random forests, were used to identify the core long non-coding RNAs (lncRNAs) with stable prognostic value for HER2-positive breast cancer.

View Article and Find Full Text PDF

Reactive oxygen species (ROS) are an unavoidable host environmental cue for intracellular pathogens such as and ; however, the signaling pathway in mycobacteria for sensing and responding to environmental stress remains largely unclear. Here, we characterize a novel CmtR-Zur-ESX3-Zn regulatory pathway in that aids mycobacterial survival under oxidative stress. We demonstrate that CmtR functions as a novel redox sensor and that its expression can be significantly induced under HO stress.

View Article and Find Full Text PDF

An unusually high lipid content and a complex lipid profile are the most distinctive features of the mycobacterial cell envelope. However, our understanding of the regulatory mechanism underlying mycobacterial lipid metabolism is limited, and the major regulators responsible for lipid homeostasis remain to be characterized. Here, we identified MmbR as a novel master regulator that is essential for maintaining lipid homeostasis in Mycolicibacterium smegmatis.

View Article and Find Full Text PDF

Mycobacterium tuberculosis is the causative agent of tuberculosis and has evolved an ability to survive in hostile host environments. M. tuberculosis is thought to utilize the rTCA cycle to sustain its latent growth during infection, but the enzymatic characteristics and physiological function for the key citrate lyase of the rTCA cycle, MtbCitE, in the important pathogen remain unclear.

View Article and Find Full Text PDF

Mycobacterium tuberculosis possesses unique cellular envelope components that contribute to bacterial escape from host immune surveillance. Phosphatidylinositol mannosides (PIMs) and their higher derivatives are important molecules implicated in host-pathogen interactions in the course of tuberculosis. However, the biosynthetic regulation of these specific lipids and its effect on the bacterial fate in the infected host remain unclear.

View Article and Find Full Text PDF

Background: Cumulative evidence suggests that long non-coding RNAs (lncRNAs) play an important role in tumorigenesis. This study aims to identify lncRNAs that can serve as new biomarkers for breast cancer diagnosis or screening.

Methods: First, the linear fitting method was used to identify differentially expressed genes from the breast cancer RNA expression profiles in The Cancer Genome Atlas (TCGA).

View Article and Find Full Text PDF

Cyclic di-GMP (c-di-GMP) is an important second messenger in bacteria, and its regulatory network has been extensively studied. However, information regarding the activation mechanisms of its receptors remains limited. In this study, we characterized the two-component regulator DevR as a new c-di-GMP receptor and further uncovered a novel co-activation mechanism for effective regulation of DevR in mycobacteria.

View Article and Find Full Text PDF

Cordycepin is an efficient component of Cordyceps spp, a traditional Chinese medicine widely used for healthcare in China, and has been recently acted as a strong anticancer agent for clinic. However, whether and how it may play a role in combating tuberculosis, caused by Mycobacterium tuberculosis, remains unknown. Here we report that cordycepin can kill Mycobacterium by hijacking the bacterial adenosine kinase (AdoK), a purine salvage enzyme responsible for the phosphorylation of adenosine (Ado) to adenosine monophosphate (AMP).

View Article and Find Full Text PDF

Hostile environmental cues cause to enter a state of slow growth for survival. However, the underlying regulatory mechanism remains unclear. DnaA is essential for DNA replication initiation and represents an efficient target for growth regulation in bacteria.

View Article and Find Full Text PDF
Article Synopsis
  • Biofilm formation in mycobacteria is regulated and involves a specific gene cluster called the mmt operon, which is crucial for mannitol metabolism and transportation.
  • The operon features genes that create a transcriptional repressor and an enzyme converting D-mannose to D-mannitol, with D-mannitol promoting biofilm formation by relieving the repressor's control.
  • Additionally, two other genes, Ms0179 and Ms0180, positively regulate the mmt operon and significantly influence biofilm development in Mycobacterium smegmatis, highlighting a unique regulatory pathway in mycobacterial biofilm formation.
View Article and Find Full Text PDF

Cyclic dimeric guanosine monophosphate (c-di-GMP) is a universally conserved second messenger that contributes to the pathogenicity of numerous bacterial species. In recent years, growing evidence has shown that bacterial extracellular c-di-GMP can interact with the innate immune system and regulate host immune responses. This review summarizes our current understanding on the dual roles of bacterial c-di-GMP in pathogen-host interaction: activation of the antibacterial innate immune response through the cytosolic surveillance pathway and inhibition of innate immune defense for iron restriction.

View Article and Find Full Text PDF

Isoniazid (INH) and ethambutol (EMB) are two major first-line drugs for managing tuberculosis (TB), caused by the microbe Although co-use of these two drugs is common in clinical practice, the mechanism for the potential synergistic interplay between them remains unclear. Here, we present first evidence that INH and EMB act synergistically through a transcriptional repressor of the gene, the target gene of INH encoding an enoyl-acyl carrier protein reductase of the fatty acid synthase type II system required for bacterial cell wall integrity. We report that EMB binds a hypothetical transcription factor encoded by the gene, designated here as EtbR.

View Article and Find Full Text PDF

Cyclic diguanylate monophosphate (c-di-GMP) is a global signaling molecule that modulates diverse cellular processes through its downstream receptors. However, no study has fully clarified the mechanisms by which c-di-GMP organizes functionally divergent regulators to drive the gene expression for coping with environmental stress. Here, we reported that c-di-GMP can integrate two functionally opposite receptor transcription factors, namely, LtmA and HpoR, into a pathway to regulate the antioxidant processes in Mycobacterium smegmatis.

View Article and Find Full Text PDF

Cyclic di-GMP (c-di-GMP) is a global signaling molecule that widely modulates diverse cellular processes. However, whether or not the c-di-GMP signal participates in regulation of bacterial antioxidant defense is unclear, and the involved regulators remain to be explored. In this study, we characterized HpoR as a novel c-di-GMP effective transcription factor and found a link between the c-di-GMP signal and the antioxidant regulation in Mycobacterium smegmatis.

View Article and Find Full Text PDF

Transport-related genes significantly affect bacterial antibiotic resistance. However, the effects of these genes and their regulation of bacterial drug resistance in several mycobacterial species, including the fast-growing Mycobacterium smegmatis, the pathogen M. tuberculosis and M.

View Article and Find Full Text PDF

Nucleoid-associated proteins (NAPs) play important roles in the global organization of bacterial chromosomes. However, potential NAPs and their functions are barely characterized in mycobacteria. In this study, NapM, an alkaline protein, functions as a new NAP.

View Article and Find Full Text PDF

Pathogens usually evade and manipulate host-immune pathways through pathogen-host protein-protein interactions (PPIs) to avoid being killed by the host immune system. Therefore, uncovering pathogen-host PPIs is critical for determining the mechanisms underlying pathogen infection and survival. In this study, we developed a computational method, which we named pairwise structure similarity (PSS)-PPI, to predict pathogen-host PPIs.

View Article and Find Full Text PDF