Regulation of toxin synthesis in Clostridium botulinum and Clostridium tetani

Abstract : Botulinum and tetanus neurotoxins are structurally and functionally related proteins that are potent inhibitors of neuroexocytosis. Botulinum neurotoxin (BoNT) associates with non-toxic proteins (ANTPs) to form complexes of various sizes, whereas tetanus toxin (TeNT) does not form any complex. The BoNT and ANTP genes are clustered in a DNA segment called the botulinum locus, which has different genomic localization (chromosome, plasmid, phage) in the various Clostridium botulinum types and subtypes. The botulinum locus genes are organized in two polycistronic operons (ntnh-bont and ha/orfX operons) transcribed in opposite orientations. A gene called botR lying between the two operons in C. botulinum type A encodes an alternative sigma factor which regulates positively the synthesis of BoNT and ANTPs at the late exponential growth phase and beginning of the stationary phase. In Clostridium tetani, the gene located immediately upstream of tent encodes a positive regulatory protein, TetR, which is related to BotR. C. botulinum and C. tetani genomes contain several two-component systems and predicted regulatory orphan genes. In C. botulinum type A, four two-component systems have been found that positively or negatively regulate the synthesis of BoNT and ANTPs independently of BotR/A. The synthesis of neurotoxin in Clostridia seems to be under the control of complex network of regulation.
Complete list of metadatas

Cited literature [13 references]  Display  Hide  Download

https://hal-pasteur.archives-ouvertes.fr/pasteur-01792396
Contributor : Floran Bidault <>
Submitted on : Wednesday, August 1, 2018 - 4:08:02 PM
Last modification on : Tuesday, September 4, 2018 - 4:34:59 PM
Long-term archiving on : Friday, November 2, 2018 - 2:36:29 PM

File

Regulation of toxinogenesis(1)...
Files produced by the author(s)

Licence


Distributed under a Creative Commons Attribution - NonCommercial - ShareAlike 4.0 International License

Identifiers

Collections

Citation

Chloé Connan, Cécile Denève, Christelle Mazuet, Michel Popoff. Regulation of toxin synthesis in Clostridium botulinum and Clostridium tetani. Toxicon, Elsevier, 2013, 75 (3), pp.90 - 100. ⟨10.1016/j.toxicon.2013.06.001⟩. ⟨pasteur-01792396⟩

Share

Metrics

Record views

69

Files downloads

192