Abstract
Many Gram-negative pathogens utilize dedicated secretion systems to export virulence factors such as exotoxins and effectors 1–4 . Several exotoxins are synthesized as precursors containing amino-terminal Sec signal peptides and are exported through the inner-membrane-bound Sec machinery to the periplasm, followed by secretion across the outer membrane to the exterior using a type II secretion system (T2SS) 3,5 . Here, we report that thermostable direct haemolysin (TDH), an exotoxin of the food-borne pathogen Vibrio parahaemolyticus, can be exported through the type III secretion system (T3SS), which engages in one-step secretion of effectors 4 , despite possessing a Sec signal peptide and being mainly secreted via the T2SS. Although the precursor of TDH is targeted to the Sec pathway, a fraction of mature TDH was observed to re-enter the bacterial cytoplasm. The N terminus of mature TDH comprises a T3SS signal sequence, allowing it to be loaded into the T3SS. We also show that T3SS-delivered TDH as an effector contributes to intestinal fluid accumulation in a rabbit diarrhoeal model of V. parahaemolyticus infection. Thus, our results show that an unconventional export mechanism for a bacterial toxin via the T3SS in tandem with the Sec machinery facilitates the virulence trait of V. parahaemolyticus.
| Original language | English |
|---|---|
| Journal | Nature Microbiology |
| DOIs | |
| Publication status | Published - Jan 1 2019 |
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ASJC Scopus subject areas
- Microbiology
- Immunology
- Applied Microbiology and Biotechnology
- Genetics
- Microbiology (medical)
- Cell Biology
Cite this
Export of a Vibrio parahaemolyticus toxin by the Sec and type III secretion machineries in tandem. / Matsuda, Shigeaki; Okada, Ryu; Tandhavanant, Sarunporn; Hiyoshi, Hirotaka; Goto, Kazuyoshi; Iida, Tetsuya; Kodama, Toshio.
In: Nature Microbiology, 01.01.2019.Research output: Contribution to journal › Letter
}
TY - JOUR
T1 - Export of a Vibrio parahaemolyticus toxin by the Sec and type III secretion machineries in tandem
AU - Matsuda, Shigeaki
AU - Okada, Ryu
AU - Tandhavanant, Sarunporn
AU - Hiyoshi, Hirotaka
AU - Goto, Kazuyoshi
AU - Iida, Tetsuya
AU - Kodama, Toshio
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Many Gram-negative pathogens utilize dedicated secretion systems to export virulence factors such as exotoxins and effectors 1–4 . Several exotoxins are synthesized as precursors containing amino-terminal Sec signal peptides and are exported through the inner-membrane-bound Sec machinery to the periplasm, followed by secretion across the outer membrane to the exterior using a type II secretion system (T2SS) 3,5 . Here, we report that thermostable direct haemolysin (TDH), an exotoxin of the food-borne pathogen Vibrio parahaemolyticus, can be exported through the type III secretion system (T3SS), which engages in one-step secretion of effectors 4 , despite possessing a Sec signal peptide and being mainly secreted via the T2SS. Although the precursor of TDH is targeted to the Sec pathway, a fraction of mature TDH was observed to re-enter the bacterial cytoplasm. The N terminus of mature TDH comprises a T3SS signal sequence, allowing it to be loaded into the T3SS. We also show that T3SS-delivered TDH as an effector contributes to intestinal fluid accumulation in a rabbit diarrhoeal model of V. parahaemolyticus infection. Thus, our results show that an unconventional export mechanism for a bacterial toxin via the T3SS in tandem with the Sec machinery facilitates the virulence trait of V. parahaemolyticus.
AB - Many Gram-negative pathogens utilize dedicated secretion systems to export virulence factors such as exotoxins and effectors 1–4 . Several exotoxins are synthesized as precursors containing amino-terminal Sec signal peptides and are exported through the inner-membrane-bound Sec machinery to the periplasm, followed by secretion across the outer membrane to the exterior using a type II secretion system (T2SS) 3,5 . Here, we report that thermostable direct haemolysin (TDH), an exotoxin of the food-borne pathogen Vibrio parahaemolyticus, can be exported through the type III secretion system (T3SS), which engages in one-step secretion of effectors 4 , despite possessing a Sec signal peptide and being mainly secreted via the T2SS. Although the precursor of TDH is targeted to the Sec pathway, a fraction of mature TDH was observed to re-enter the bacterial cytoplasm. The N terminus of mature TDH comprises a T3SS signal sequence, allowing it to be loaded into the T3SS. We also show that T3SS-delivered TDH as an effector contributes to intestinal fluid accumulation in a rabbit diarrhoeal model of V. parahaemolyticus infection. Thus, our results show that an unconventional export mechanism for a bacterial toxin via the T3SS in tandem with the Sec machinery facilitates the virulence trait of V. parahaemolyticus.
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UR - http://www.scopus.com/inward/citedby.url?scp=85061729397&partnerID=8YFLogxK
U2 - 10.1038/s41564-019-0368-y
DO - 10.1038/s41564-019-0368-y
M3 - Letter
C2 - 30778145
AN - SCOPUS:85061729397
JO - Nature Microbiology
JF - Nature Microbiology
SN - 2058-5276
ER -