PMID- 35658521
OWN - NLM
STAT- MEDLINE
DCOM- 20220720
LR  - 20221207
IS  - 1098-5530 (Electronic)
IS  - 0021-9193 (Print)
IS  - 0021-9193 (Linking)
VI  - 204
IP  - 7
DP  - 2022 Jul 19
TI  - Pseudomonas aeruginosa Secretes the Oxylipin Autoinducer Synthases OdsA and OdsB 
      via the Xcp Type 2 Secretion System.
PG  - e0011422
LID - 10.1128/jb.00114-22 [doi]
LID - e00114-22
AB  - The oxylipin-dependent quorum-sensing system (ODS) of Pseudomonas aeruginosa 
      relies on the production and sensing of two extracellular oxylipins, 
      10S-hydroxy-(8E)-octadecenoic acid (10-HOME) and 
      7S,10S-dihydroxy-(8E)-octadecenoic acid (7,10-DiHOME). Here, we implemented a 
      genetic screen of P. aeruginosa strain PAO1 aimed to identify genes required for 
      10-HOME and 7,10-DiHOME production. Among the 14 genes identified, four encoded 
      previously known components of the ODS and 10 encoded parts of the Xcp type II 
      secretion system (T2SS). We subsequently created a clean xcpQ deletion mutant, 
      which encodes the necessary outer membrane component of Xcp, and found it 
      recapitulated the impaired functionality of the T2SS transposon mutants. Further 
      studies showed that the DeltaxcpQ mutant was unable to secrete the oxylipin synthase 
      enzymes across the outer membrane. Specifically, immunoblotting for OdsA, which 
      is responsible for the generation of 10-HOME from oleic acid, detected the enzyme 
      in supernatants from wild-type PAO1 but not DeltaxcpQ cultures. Likewise, 
      chromatography of supernatants found that 10-HOME was not in supernatants 
      collected from the DeltaxcpQ mutant. Accordingly, diol synthase activity was 
      increased in the periplasm of DeltaxcpQ mutant consistent with a stoppage in its 
      transport. Importantly, after exposure of the DeltaxcpQ mutant to exogenous 10-HOME 
      and 7,10-DiHOME, the ODS effector genes become active; thus, the sensing 
      component of the ODS does not involve the T2SS. Finally, we observed that Xcp 
      contributed to robust in vitro and in vivo biofilm formation in oleic acid 
      availability- and ODS-dependent manner. Thus, T2SS-mediated transport of the 
      oxylipin synthase enzymes to outside the bacterial cell is required for ODS 
      functionality. IMPORTANCE We previously showed that the ODS of P. aeruginosa 
      produces and responds to oxylipins derived from host oleic acid by enhancing 
      biofilm formation and virulence. Here, we developed a genetic screen strategy to 
      explore the molecular basis for oxylipins synthesis and detection. Unexpectedly, 
      we found that the ODS autoinducer synthases cross the outer membrane using the 
      Xcp type 2 secretion system (T2SS) of P. aeruginosa, and so the biosynthesis of 
      oxylipins occurs extracellularly. T2SS promoted biofilm formation in the presence 
      of oleic acid as a result of ODS activation. Our results identify two new T2SS 
      secreted proteins in P. aeruginosa and reveal a new way by which this important 
      opportunistic pathogen interacts with the host environment.
FAU - Martinez, Eriel
AU  - Martinez E
AD  - Department of Microbiology, The University of Alabama at Birminghamgrid.265892.2, 
      Birmingham, Alabama, USA.
FAU - Orihuela, Carlos J
AU  - Orihuela CJ
AUID- ORCID: 0000-0002-8542-4069
AD  - Department of Microbiology, The University of Alabama at Birminghamgrid.265892.2, 
      Birmingham, Alabama, USA.
FAU - Campos-Gomez, Javier
AU  - Campos-Gomez J
AD  - Cystic Fibrosis Research Center, The University of Alabama at 
      Birminghamgrid.265892.2, Birmingham, Alabama, USA.
LA  - eng
GR  - P30 DK072482/DK/NIDDK NIH HHS/United States
GR  - AI114800/HHS | National Institutes of Health (NIH)/
GR  - R21 AI148368/AI/NIAID NIH HHS/United States
GR  - R01 AI156898/AI/NIAID NIH HHS/United States
GR  - R01 AI114800/AI/NIAID NIH HHS/United States
GR  - AI148368/HHS | National Institutes of Health (NIH)/
GR  - AI156898/HHS | National Institutes of Health (NIH)/
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20220606
PL  - United States
TA  - J Bacteriol
JT  - Journal of bacteriology
JID - 2985120R
RN  - 0 (Bacterial Proteins)
RN  - 0 (Oxylipins)
RN  - 0 (Type II Secretion Systems)
RN  - 2UMI9U37CP (Oleic Acid)
SB  - IM
MH  - Bacterial Proteins/metabolism
MH  - Oleic Acid/metabolism
MH  - Oxylipins/metabolism
MH  - Pseudomonas aeruginosa/genetics/metabolism
MH  - *Type II Secretion Systems/metabolism
PMC - PMC9295564
OTO - NOTNLM
OT  - Pseudomonas aeruginosa
OT  - autoinducer
OT  - oleic acid
OT  - oxylipin
OT  - quorum sensing
OT  - type 2 secretion system
COIS- The authors declare no conflict of interest.
EDAT- 2022/06/07 06:00
MHDA- 2022/07/22 06:00
PMCR- 2022/12/06
CRDT- 2022/06/06 09:29
PHST- 2022/06/07 06:00 [pubmed]
PHST- 2022/07/22 06:00 [medline]
PHST- 2022/06/06 09:29 [entrez]
PHST- 2022/12/06 00:00 [pmc-release]
AID - 00114-22 [pii]
AID - jb.00114-22 [pii]
AID - 10.1128/jb.00114-22 [doi]
PST - ppublish
SO  - J Bacteriol. 2022 Jul 19;204(7):e0011422. doi: 10.1128/jb.00114-22. Epub 2022 Jun 
      6.