PMID- 31409687
OWN - NLM
STAT- MEDLINE
DCOM- 20200505
LR  - 20200505
IS  - 2150-7511 (Electronic)
VI  - 10
IP  - 4
DP  - 2019 Aug 13
TI  - Role of Flagellin-Homologous Proteins in Biofilm Formation by Pathogenic Vibrio 
      Species.
LID - 10.1128/mBio.01793-19 [doi]
LID - e01793-19
AB  - The pathogenic bacterium Vibrio vulnificus exhibits the ability to form biofilm, 
      for which initiation is dependent upon swimming motility by virtue of a polar 
      flagellum. The filament of its flagellum is composed of multiple flagellin 
      subunits, FlaA, -B, -C, and -D. In V. vulnificus genomes, however, open reading 
      frames (ORFs) annotated by FlaE and -F are also present. Although neither FlaE 
      nor FlaF is involved in filament formation and cellular motility, they are well 
      expressed and secreted to the extracellular milieu through the secretion 
      apparatus for flagellar assembly. In the extrapolymeric matrix of V. vulnificus 
      biofilm, significant levels of FlaEF were detected. Mutants defective in both 
      flaE and flaF formed significantly decreased biofilms compared to the wild-type 
      biofilm. Thus, the potential role of FlaEF during the biofilm-forming process was 
      investigated by exogenous addition of recombinant FlaEF (rFlaEF) to the biofilm 
      assays. The added rFlaE and rFlaF were predominantly incorporated into the 
      biofilm matrix formed by the wild type. However, biofilms formed by a mutant 
      defective in exopolysaccharide (EPS) biosynthesis were not affected by added 
      FlaEF. These results raised a possibility that FlaEF specifically interact with 
      EPS within the biofilm matrix. In vitro pulldown assays using His-tagged rFlaEF 
      or rFlaC revealed the specific binding of EPS to rFlaEF but not to rFlaC. Taken 
      together, our results demonstrate that V. vulnificus FlaEF, flagellin-homologous 
      proteins (FHPs), are crucial for biofilm formation by directly interacting with 
      the essential determinant for biofilm maturation, EPS. Further analyses performed 
      with other pathogenic Vibrio species demonstrated both the presence of FHPs and 
      their important role in biofilm formation.IMPORTANCE Flagellar filaments of the 
      pathogenic Vibrio species, including V. vulnificus, V. parahaemolyticus, and V. 
      cholerae, are composed of multiple flagellin subunits. In their genomes, however, 
      there are higher numbers of the ORFs encoding flagellin-like proteins than the 
      numbers of flagellin subunits required for filament assembly. Since these 
      flagellin-homologous proteins (FHPs) are well expressed and excreted to 
      environments via a flagellin transport channel, their extracellular role in the 
      pathogenic Vibrio has been enigmatic. Their biological significance, which is not 
      related with flagellar functions, has been revealed to be in maturation of 
      biofilm structures. Among various components of the extracellular polymeric 
      matrix produced in the V. vulnificus biofilms, the exopolysaccharides (EPS) are 
      dominant constituents and crucial in maturation of biofilms. The enhancing role 
      of the V. vulnificus FHPs in biofilm formation requires the presence of EPS, as 
      indicated by highly specific interactions among two FHPs and three EPS.
CI  - Copyright (c) 2019 Jung et al.
FAU - Jung, You-Chul
AU  - Jung YC
AD  - Department of Life Science, Sogang University, Seoul, South Korea.
FAU - Lee, Mi-Ae
AU  - Lee MA
AD  - Department of Life Science, Sogang University, Seoul, South Korea.
FAU - Lee, Kyu-Ho
AU  - Lee KH
AD  - Department of Life Science, Sogang University, Seoul, South Korea 
      kyuholee@sogang.ac.kr.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20190813
PL  - United States
TA  - mBio
JT  - mBio
JID - 101519231
RN  - 0 (Polysaccharides, Bacterial)
RN  - 12777-81-0 (Flagellin)
SB  - IM
MH  - Biofilms/*growth & development
MH  - Extracellular Polymeric Substance Matrix/metabolism
MH  - Flagella/genetics/metabolism
MH  - Flagellin/genetics/*metabolism
MH  - Locomotion
MH  - Mutation
MH  - Open Reading Frames
MH  - Polysaccharides, Bacterial/genetics/metabolism
MH  - Secretory Pathway
MH  - Transcription, Genetic
MH  - Vibrio/genetics/*pathogenicity/*physiology
MH  - Vibrio vulnificus/genetics/pathogenicity/physiology
PMC - PMC6692518
OTO - NOTNLM
OT  - Vibrio
OT  - biofilm matrix
OT  - exopolysaccharides
OT  - flagellin-homologous proteins
EDAT- 2019/08/15 06:00
MHDA- 2020/05/06 06:00
PMCR- 2019/08/13
CRDT- 2019/08/15 06:00
PHST- 2019/08/15 06:00 [entrez]
PHST- 2019/08/15 06:00 [pubmed]
PHST- 2020/05/06 06:00 [medline]
PHST- 2019/08/13 00:00 [pmc-release]
AID - mBio.01793-19 [pii]
AID - mBio01793-19 [pii]
AID - 10.1128/mBio.01793-19 [doi]
PST - epublish
SO  - mBio. 2019 Aug 13;10(4):e01793-19. doi: 10.1128/mBio.01793-19.