The regulator HlyU, the repeat-in-toxin gene rtxA1, and their roles in the pathogenesis of Vibrio vulnificus infections
نویسندگان
چکیده
HlyU is a master regulator that plays an essential role in the virulence of the human pathogen Vibrio vulnificus. One of the most noteworthy characteristics of HlyU regulation in this organism is its positive control of the expression of the repeat-in-toxin (RtxA1) gene, one of the most important virulence factors accounting for the fulminating and damaging nature of V. vulnificus infections. In this work, we reviewed the latest studies of RtxA1 in this bacterium and highlight the mechanism of gene regulation of rtxA1 expression by HlyU under a broader gene regulatory network.
منابع مشابه
The HlyU protein is a positive regulator of rtxA1, a gene responsible for cytotoxicity and virulence in the human pathogen Vibrio vulnificus.
Vibrio vulnificus is an opportunistic human pathogen that preferentially infects compromised iron-overloaded patients, causing a fatal primary septicemia with very rapid progress, resulting in a high mortality rate. In this study we determined that the HlyU protein, a virulence factor in V. vulnificus CMCP6, up-regulates the expression of VV20479, a homologue of the Vibrio cholerae RTX (repeats...
متن کاملRegulation of cytotoxicity by quorum-sensing signaling in Vibrio vulnificus is mediated by SmcR, a repressor of hlyU.
Cytotoxicity is an important virulence determinant in the pathogenesis of Vibrio vulnificus, and two cytotoxins, RTX (encoded by rtxA1) and cytolysin/hemolysin (encoded by vvhA), have been identified in this organism. We showed that the quorum-sensing regulator LuxO controlled the cytotoxicity of this organism: a ΔluxO mutant exhibited low cytotoxicity, whereas a constitutively activated luxO m...
متن کاملIdentification of the target DNA sequence and characterization of DNA binding features of HlyU, and suggestion of a redox switch for hlyA expression in the human pathogen Vibrio cholerae from in silico studies
HlyU, a transcriptional regulator common in many Vibrio species, activates the hemolysin gene hlyA in Vibrio cholerae, the rtxA1 operon in Vibrio vulnificus and the genes of plp-vah1 and rtxACHBDE gene clusters in Vibrio anguillarum. The protein is also proposed to be a potential global virulence regulator for V. cholerae and V. vulnificus. Mechanisms of gene control by HlyU in V. vulnificus an...
متن کاملVibrio vulnificus RtxA1 Toxin Expression Upon Contact With Host Cells Is RpoS-Dependent
The expression of virulence genes in bacteria is known to be regulated by various environmental and host factors. Vibrio vulnificus, an estuarine bacterium, experiences a dramatic environmental change during its infection process. We reported that V. vulnificus RtxA1 toxin caused acute cell death only when close contact to host cells was allowed. A sigma factor RpoS is a very important regulato...
متن کاملDomain organization and evolution of multifunctional autoprocessing repeats-in-toxin (MARTX) toxin in Vibrio vulnificus.
The objective of this study was to analyze multifunctional autoprocessing repeats-in-toxin (MARTX) toxin domain organization within the aquatic species Vibrio vulnificus as well as to study the evolution of the rtxA1 gene. The species is subdivided into three biotypes that differ in host range and geographical distribution. We have found three different types (I, II, and III) of V. vulnificus M...
متن کامل