scholarly journals Mutations in enterobacterial common antigen biosynthesis restore outer membrane barrier function in Escherichia coli tol‐pal mutants

2020 ◽  
Vol 114 (6) ◽  
pp. 991-1005
Author(s):  
Xiang’Er Jiang ◽  
Wee Boon Tan ◽  
Rahul Shrivastava ◽  
Deborah Chwee San Seow ◽  
Swaine Lin Chen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane ◽  
Barrier Function ◽  
Common Antigen ◽  
Enterobacterial Common Antigen ◽  
Membrane Barrier

scholarly journals Mutations in enterobacterial common antigen biosynthesis restore outer membrane barrier function in Escherichia coli tol-pal mutants

2018 ◽  
Author(s):  
Xiang’Er Jiang ◽  
Wee Boon Tan ◽  
Rahul Shrivastava ◽  
Deborah Chwee San Seow ◽  
Swaine Lin Chen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane ◽  
Barrier Function ◽  
Lipid Homeostasis ◽  
Common Antigen ◽  
Potential Mechanism ◽  
External Threats ◽  
Enterobacterial Common Antigen ◽  
Lipid Species ◽  
Membrane Barrier

SummaryThe outer membrane (OM) is an essential component of the Gram-negative bacterial envelope that protects cells against external threats. To maintain a functional OM, cells require distinct mechanisms to ensure balance of proteins and lipids in the membrane. Mutations in OM biogenesis and/or homeostasis pathways often result in permeability defects, but how molecular changes in the OM affect barrier function is unclear. Here, we seek potential mechanism(s) that can alleviate permeability defects in Escherichia coli cells lacking the Tol-Pal complex, which accumulate excess PLs in the OM. We identify mutations in enterobacterial common antigen (ECA) biosynthesis that re-establish OM barrier function against large hydrophilic molecules, yet did not restore lipid homeostasis. Furthermore, we demonstrate that build-up of biosynthetic intermediates, but not loss of ECA itself, contributes to the rescue. This suppression of OM phenotypes is unrelated to known effects that accumulation of ECA intermediates have on the cell wall. Finally, we reveal that an unusual diacylglycerol pyrophosphoryl-linked lipid species also accumulates in ECA mutants, and might play a role in the rescue phenotype. Our work provides insights into how OM barrier function can be restored independent of lipid homeostasis, and highlights previously unappreciated effects of ECA-related species in OM biology.

scholarly journals Accumulation of the Enterobacterial Common Antigen Lipid II Biosynthetic Intermediate StimulatesdegP Transcription in Escherichia coli

1998 ◽  
Vol 180 (22) ◽  
pp. 5875-5884 ◽  
Author(s):  
Paul N. Danese ◽  
George R. Oliver ◽  
Kathleen Barr ◽  
Gregory D. Bowman ◽  
Paul D. Rick ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Signal Transduction ◽  
Heat Shock ◽  
Outer Membrane ◽  
Common Antigen ◽  
E Coli ◽  
Outer Leaflet ◽  
Lipid Ii ◽  
Enterobacterial Common Antigen ◽  
Two Component Signal Transduction

ABSTRACT In Escherichia coli, transcription of thedegP locus, which encodes a heat-shock-inducible periplasmic protease, is controlled by two parallel signal transduction systems that each monitor extracytoplasmic protein physiology. For example, the heat-shock-inducible sigma factor, ςE, controls degP transcription in response to the overproduction and folded state of various extracytoplasmic proteins. Similarly, the CpxA/R two-component signal transduction system increases degP transcription in response to the overproduction of a variety of extracytoplasmic proteins. SincedegP transcription is attuned to the physiology of extracytoplasmic proteins, we were interested in identifying negative transcriptional regulators of degP. To this end, we screened for null mutations that increased transcription from a strain containing a degP-lacZ reporter fusion. Through this approach, we identified null mutations in the wecE,rmlA ECA, and wecF loci that increase degP transcription. Interestingly, each of these loci is responsible for synthesis of the enterobacterial common antigen (ECA), a glycolipid situated on the outer leaflet of the outer membrane of members of the family Enterobacteriaceae. However, these null mutations do not stimulate degP transcription by eliminating ECA biosynthesis. Rather, the wecE,rmlA ECA, and wecF null mutations each impede the same step in ECA biosynthesis, and it is the accumulation of the ECA biosynthetic intermediate, lipid II, that causes the observed perturbations. For example, the lipid II-accumulating mutant strains each (i) confer upon E. colia sensitivity to bile salts, (ii) confer a sensitivity to the synthesis of the outer membrane protein LamB, and (iii) stimulate both the Cpx pathway and ςE activity. These phenotypes suggest that the accumulation of lipid II perturbs the structure of the bacterial outer membrane. Furthermore, these results underscore the notion that although the Cpx and ςE systems function in parallel to regulate degP transcription, they can be simultaneously activated by the same perturbation.

Occurrence and structure of cyclic Enterobacterial Common Antigen in Escherichia coli O157:H−

2012 ◽  
Vol 363 ◽  
pp. 29-32 ◽  
Author(s):  
Eleonora Fregolino ◽  
Radka Ivanova ◽  
Rosa Lanzetta ◽  
Antonio Molinaro ◽  
Michelangelo Parrilli ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Escherichia Coli O157 ◽  
Common Antigen ◽  
Enterobacterial Common Antigen

scholarly journals ElyC and Cyclic Enterobacterial Common Antigen Regulate Synthesis of Phosphoglyceride-Linked Enterobacterial Common Antigen

mBio ◽  
2021 ◽  
Author(s):  
Ashutosh K. Rai ◽  
Joseph F. Carr ◽  
David E. Bautista ◽  
Wei Wang ◽  
Angela M. Mitchell
Keyword(s):  
Klebsiella Pneumoniae ◽  
Yersinia Pestis ◽  
Outer Membrane ◽  
Salmonella Enterica ◽  
Pathogenic Bacteria ◽  
Permeability Barrier ◽  
Common Antigen ◽  
Content Type ◽  
Enterobacterial Common Antigen ◽  
The Many

Enterobacterial common antigen (ECA) is a conserved polysaccharide present on the surface of the outer membrane (OM) and in the periplasm of the many pathogenic bacteria belonging to Enterobacterales , including Klebsiella pneumoniae , Salmonella enterica , and Yersinia pestis . As the OM is a permeability barrier that excludes many antibiotics, synthesis pathways for OM molecules are promising targets for antimicrobial discovery.

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