Regulated Assembly of LPS, Its Structural Alterations and Cellular Response to LPS Defects

Klein, Gracjana; Raina, Satish

doi:10.3390/ijms20020356

Cited by 95 publications

(130 citation statements)

References 86 publications

Supporting

Mentioning

128

Contrasting

Order By: Relevance

“…Our results also highlight that phage infectivity depends on the host cellular physiology and, in particular, membrane characteristics of the host imparted by LPS and outer membrane protein biogenesis pathways [108,109,203]. For instance, our results indicate that the disruptions in LPS (for example, deletions or downregulation of waa genes Fig.…”

Section: Discussionsupporting

confidence: 53%

“…We also observed higher fitness scores for a number of genes involved in LPS biosynthesis (waaC, waaD, waaE, waaF, lpcA) in the presence of T4, LZ4 and λ phages when grown on solid plates. These results suggest that LPS components either play an important role in efficient phage infection cycle or these LPS truncations lead to a destabilized membrane and probably decrease outer membrane protein levels via envelope stress response [101,[106][107][108][109]. A detailed description about many of the genes we identified in this study is included as a Supplemental Note.…”

Section: Rb-tnseq Identifies Known Receptors and Host Factors For Allmentioning

confidence: 91%

“…For example, it is known that the downregulation of genes involved in transcription antitermination (nusB, nusG) and Sec translocon subunit E (secE) shows high fitness in presence of λ phage, and are crucial for the phage growth cycle [118][119][120]. lptABC, kdsC, and lpxAC are known to impact outer membrane biogenesis, LPS synthesis and transport [108,109,121,122]; while the RNA binding global regulator CsrA is known to be involved in carbohydrate metabolism and regulation of biofilm [123,124]. Downregulation of these genes likely leads to pleiotropic effects leading to enhanced fitness in the presence of phages.…”

Section: A Crispri Screen Provides Deeper View Of Phage Resistance Dementioning

confidence: 99%

See 2 more Smart Citations

High-throughput mapping of the phage resistance landscape inE. coli

Mutalik¹,

Adler²,

Rishi³

et al. 2020

Preprint

View full text Add to dashboard Cite

Bacteriophages (phages) are critical players in the dynamics and function of microbial communities and drive processes as diverse as global biogeochemical cycles and human health. Phages tend to be predators finely tuned to attack specific hosts, even down to the strain level, which in turn defend themselves using an array of mechanisms. However, to date, efforts to rapidly and comprehensively identify bacterial host factors important in phage infection and resistance have yet to be fully realized. Here, we globally map the host genetic determinants involved in resistance to 14 phylogenetically diverse double-stranded DNA phages using two model Escherichia coli strains (K-12 and BL21) with known sequence divergence to demonstrate strain-specific differences. Using genome-wide loss-of-function and gain-of-function genetic technologies, we are able to confirm previously described phage receptors as well as uncover a number of previously unknown host factors that confer resistance to one or more of these phages. We uncover differences in resistance factors that strongly align with the susceptibility of K-12 and BL21 to specific phage. We also identify both phage specific mechanisms, such as the unexpected role of cyclic-di-GMP in host sensitivity to phage N4, and more generic defenses, such as the overproduction of colanic acid capsular polysaccharide that defends against a wide array of phages. Our results indicate that host responses to phages can occur via diverse cellular mechanisms. Our systematic and highthroughput genetic workflow to characterize phage-host interaction determinants can be extended to diverse bacteria to generate datasets that allow predictive models of how phagemediated selection will shape bacterial phenotype and evolution. The results of this study and future efforts to map the phage resistance landscape will lead to new insights into the coevolution of hosts and their phage, which can ultimately be used to design better phage therapeutic treatments and tools for precision microbiome engineering.3 Introduction:

show abstract

Section: Discussionsupporting

confidence: 53%

Section: Rb-tnseq Identifies Known Receptors and Host Factors For Allmentioning

confidence: 91%

Section: A Crispri Screen Provides Deeper View Of Phage Resistance Dementioning

confidence: 99%

See 1 more Smart Citation

High-throughput mapping of the phage resistance landscape inE. coli

Mutalik¹,

Adler²,

Rishi³

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…Previous studies have shown that deletion of yciM is tolerated in E. coli lacking lpp (13,16). It is thought that deletion of lpp restores OM lipid balance in the yciM mutant by increasing the number of acyl chains available for PL biosynthesis (16,20). As seen in (Fig.…”

Section: Resultsmentioning

confidence: 85%

“…It has previously been shown that deletion of the highly abundant lipoprotein Lpp, which tethers the OM to the underlying peptidoglycan, can suppress deletion of yciM (13,(16)(17)(18). As Lpp is anchored to the OM by three acyl chains (19), it has been hypothesized that loss of lpp restores lipid balance in the ΔyciM mutant by increasing the number of acyl chains available for PL biosynthesis (16,20).…”

mentioning

confidence: 99%

YejM Modulates Activity of the YciM/FtsH Protease Complex To Prevent Lethal Accumulation of Lipopolysaccharide

Guest

Guerra

Wissler

et al. 2020

mBio

View full text Add to dashboard Cite

Lipopolysaccharide (LPS) is an essential glycolipid present in the outer membrane (OM) of many Gram-negative bacteria. Balanced biosynthesis of LPS is critical for cell viability; too little LPS weakens the OM, while too much LPS is lethal. In Escherichia coli, this balance is maintained by the YciM/FtsH protease complex, which adjusts LPS levels by degrading the LPS biosynthesis enzyme LpxC. Here, we provide evidence that activity of the YciM/FtsH protease complex is inhibited by the essential protein YejM. Using strains in which LpxC activity is reduced, we show that yciM is epistatic to yejM, demonstrating that YejM acts upstream of YciM to prevent toxic overproduction of LPS. Previous studies have shown that this toxicity can be suppressed by deleting lpp, which codes for a highly abundant OM lipoprotein. It was assumed that deletion of lpp restores lipid balance by increasing the number of acyl chains available for glycerophospholipid biosynthesis. We show that this is not the case. Rather, our data suggest that preventing attachment of lpp to the peptidoglycan sacculus allows excess LPS to be shed in vesicles. We propose that this loss of OM material allows continued transport of LPS to the OM, thus preventing lethal accumulation of LPS within the inner membrane. Overall, our data justify the commitment of three essential inner membrane proteins to avoid toxic over- or underproduction of LPS. IMPORTANCE Gram-negative bacteria are encapsulated by an outer membrane (OM) that is impermeable to large and hydrophobic molecules. As such, these bacteria are intrinsically resistant to several clinically relevant antibiotics. To better understand how the OM is established or maintained, we sought to clarify the function of the essential protein YejM in Escherichia coli. Here, we show that YejM inhibits activity of the YciM/FtsH protease complex, which regulates synthesis of the essential OM glycolipid lipopolysaccharide (LPS). Our data suggest that disrupting proper communication between LPS synthesis and transport to the OM leads to accumulation of LPS within the inner membrane (IM). The lethality associated with this event can be suppressed by increasing OM vesiculation. Our research has identified a completely novel signaling pathway that we propose coordinates LPS synthesis and transport.

show abstract

Overexpression of the key genes in the biosynthetic pathways of lipid A and peptidoglycan in Escherichia coli

Yong

Qiao

et al. 2022

Biotech and App Biochem

View full text Add to dashboard Cite

Gram-negative bacterium Escherichia coli has a tripartite cell envelope with a cytoplasmic membrane, a peptidoglycan layer, and an asymmetric outer membrane containing lipopolysaccharide in its outer leaflet. The biogenesis of peptidoglycan and lipopolysaccharide shares the same substrate UDP-GlcNAc. From UDP-GlcNAc, MurA catalyzes the first reaction for peptidoglycan biosynthesis, while LpxA catalyzes the first reaction for lipopolysaccharide biosynthesis. This study demonstrates that murA overexpression in E. coli MG1655 inhibited the cell growth and increased the cell length, whereas lpxA overexpression in MG1655 neither inhibited the cell growth nor increased the cell length. Further study showed that individual overexpression of the other eight genes encoding the enzymes to catalyze the initial reactions in the biosynthetic pathway of lipopolysaccharide did not inhibit the cell growth. When MG1655/pBad-lpxA, MG1655/pBad-lpxD, and MG1655/pBad-lpxH were transformed with pFW01-thrA*BC-rhtC that contains the key genes for L-threonine biosynthesis and transport, the L-threonine production was increased. The L-threonine production in MG1655/pFW01-thrA*BC-rhtC/pBad-lpxH increased 46.1% as compared to the control MG1655/pFW01-thrA*BC-rhtC/pBad.

show abstract

Regulated Assembly of LPS, Its Structural Alterations and Cellular Response to LPS Defects

Cited by 95 publications

References 86 publications

High-throughput mapping of the phage resistance landscape inE. coli

High-throughput mapping of the phage resistance landscape inE. coli

YejM Modulates Activity of the YciM/FtsH Protease Complex To Prevent Lethal Accumulation of Lipopolysaccharide

Overexpression of the key genes in the biosynthetic pathways of lipid A and peptidoglycan in Escherichia coli

Contact Info

Product

Resources

About