title: Effects of depletion of RNA-binding protein Tex on the expression of toxin genes in Clostridium perfringens.
abstract: Tex was originally identified in Bordetella pertussis, where it serves as a transcriptional regulator of toxin genes. However, the Tex of Streptococcus pneumoniae has no regulatory function in the expression of the pneumococcal major toxin pneumolysin. Here, we identified the CPE2168 gene as Tex in Clostridium perfringens, and examined the roles of Tex in toxin gene expression. We found that the deletion mutant for Tex does not affect growth, but the mRNA levels of three hyaluronidase genes (nagH, nagJ, and nagL) and an exo-sialidase (nanJ) were reduced to less than 50% as compared to the parent strain, C. perfringens strain 13. On the other hand, Tex did not affect the expression of proteases, enterotoxins, hemolysins, either of two hyaluronidase genes (nagI and nagK), an exo-sialidase (nanI), or adhesins. Moreover, purified Tex bound to the 5'-portion of target gene mRNAs. Based on these results, we propose that Tex positively regulates the gene expression of a set of toxin genes in C. perfringens.
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Kimihiro
authors.initials: K
authors.lastname: Abe
authors.forename: Nozomu
authors.initials: N
authors.lastname: Obana
authors.forename: Kouji
authors.initials: K
authors.lastname: Nakamura
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001427:Bacterial Toxins / Q000235:genetics*; D001483:Base Sequence; D003016:Clostridium perfringens / Q000235:genetics* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006821:Hyaluronoglucosaminidase / Q000235:genetics; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D006821:Hyaluronoglucosaminidase