Genetic Analysis of 15 Protein Folding Factors and Proteases of the Escherichia coli Cell Envelope

Weski, Juliane; Ehrmann, Michael

doi:10.1128/jb.00221-12

Cited by 27 publications

(30 citation statements)

References 73 publications

(81 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A tsp (prc) mutation produced synthetic phenotypes with degP, ppiD, surA, fkpA, and ydgD, each with a known or putative role in protein quality control. In addition, bacteria with defects at surA, dsbA, and various combinations of quality control or protease loci grew poorly at high salinity (33).…”

Section: Discussionmentioning

confidence: 99%

Salinity-Dependent Impacts of ProQ, Prc, and Spr Deficiencies on Escherichia coli Cell Structure

et al. 2014

View full text Add to dashboard Cite

ProQ is a cytoplasmic protein with RNA chaperone activities that reside in FinO-and Hfq-like domains. Lesions at proQ decrease the level of the osmoregulatory glycine betaine transporter ProP. Lesions at proQ eliminated ProQ and Prc, the periplasmic protease encoded by the downstream gene prc. They dramatically slowed the growth of Escherichia coli populations and altered the morphologies of E. coli cells in high-salinity medium. ProQ and Prc deficiencies were associated with different phenotypes. ProQ-deficient bacteria were elongated unless glycine betaine was provided. High-salinity cultures of Prcdeficient bacteria included spherical cells with an enlarged periplasm and an eccentric nucleoid. The nucleoid-containing compartment was bounded by the cytoplasmic membrane and peptidoglycan. This phenotype was not evident in bacteria cultivated at low or moderate salinity, nor was it associated with murein lipoprotein (Lpp) deficiency, and it differed from those elicited by the MreB inhibitor A-22 or the FtsI inhibitor aztreonam at low or high salinity. It was suppressed by deletion of spr, which encodes one of three murein hydrolases that are redundantly essential for enlargement of the murein sacculus. Prc deficiency may alter bacterial morphology by impairing control of Spr activity at high salinity. ProQ and Prc deficiencies lowered the ProP activity of bacteria cultivated at moderate salinity by approximately 70% and 30%, respectively, but did not affect other osmoregulatory functions. The effects of ProQ and Prc deficiencies on ProP activity are indirect, reflecting their roles in the maintenance of cell structure.O smotic stress perturbs cell structure, composition, and function (1). Despite retaining their rod-like shape, Escherichia coli cells cultivated in high-salinity minimal medium maintain lower hydration, turgor pressure, and growth rate than those cultivated at a lower salinity that is optimal for growth (2). The elastic murein sacculus is believed to buffer effects of osmotically induced water fluxes on cell structure (3). E. coli can attenuate osmotically induced dehydration by accumulating small, uncharged, or zwitterionic organic solutes called osmolytes (1, 4, 5). For example, transporter ProP mediates the accumulation of diverse solutes, including proline and glycine betaine, thereby restoring cellular hydration and stimulating bacterial growth in high-salinity media (6, 7).ProQ is a cytoplasmic protein that binds RNA, facilitating RNA duplexing and strand exchange (8). Previous work showed that proQ lesions decreased ProP levels and attenuated ProP activity (the proQ transport phenotype). These effects occurred when bacteria expressed proP from the chromosome or a plasmid-based P BAD promoter during growth in low-to moderate-salinity media and were reversed by plasmid-based proQ expression (8, 9). Here, we show that proQ lesions dramatically slow the growth of E. coli populations in high-salinity medium and alter the morphologies of E. coli cells (the proQ growth and morphological phenotypes...

show abstract

Section: Discussionmentioning

confidence: 99%

Salinity-Dependent Impacts of ProQ, Prc, and Spr Deficiencies on Escherichia coli Cell Structure

et al. 2014

View full text Add to dashboard Cite

show abstract

“…The genetic and physical interactions between BepA and the BAM complex raise the possibility that BepA promotes the correct assembly of not only LptD but also other OMPs. The surA/bepA double disruptant was recently reported to exhibit a temperature-sensitive growth phenotype (49). Lack of SurA would produce misfolded BamA that could be normally eliminated by BepA, and the growth defects of the surA/bepA double disruptant may result from dysfunction of the BAM complex to assemble OMPs.…”

Section: Discussionmentioning

confidence: 99%

Protease homolog BepA (YfgC) promotes assembly and degradation of β-barrel membrane proteins in Escherichia coli

Narita

Masui

Suzuki

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

135

View full text Add to dashboard Cite

Gram-negative bacteria are equipped with quality-control systems for the outer membrane (OM) that sense and cope with defective biogenesis of its components. Accumulation of misfolded outer membrane proteins (OMPs) in Escherichia coli leads to activation of σ E , an essential alternative σ factor that up-regulates transcription of multiple genes required to preserve OM structure and function. Disruption of bepA (formerly yfgC), a σ E -regulated gene encoding a putative periplasmic metalloprotease, sensitizes cells to multiple drugs, suggesting that it may be involved in maintaining OM integrity. However, the specific function of BepA remains unclear. Here, we show that BepA enhances biogenesis of LptD, an essential OMP involved in OM transport and assembly of lipopolysaccharide, by promoting rearrangement of intramolecular disulfide bonds of LptD. In addition, BepA possesses protease activity and is responsible for the degradation of incorrectly folded LptD. In the absence of periplasmic chaperone SurA, BepA also promotes degradation of BamA, the central OMP subunit of the β-barrel assembly machinery (BAM) complex. Interestingly, defective oxidative folding of LptD caused by bepA disruption was partially suppressed by expression of protease-active site mutants of BepA, suggesting that BepA functions independently of its protease activity. We also show that BepA has genetic and physical interaction with components of the BAM complex. These findings raised the possibility that BepA maintains the integrity of OM both by promoting assembly of OMPs and by proteolytically eliminating OMPs when their correct assembly was compromised.extracytoplasmic function sigma factor | protein quality control | disulfide bond formation | peptidase M48 | tetratricopeptide repeat (TPR) motif

show abstract

“…Transport-A ⌬ppiD strain shows enhanced sensitivity toward SDS and EDTA, which is commonly associated with defects in outer membrane and cell envelope assembly (45). We therefore analyzed the influence of PpiD on outer membrane protein transport across the SecYEG translocon in an in vitro transcription/translation system employing purified INV of a ⌬ppiD strain.…”

Section: The Lack Of Ppid Does Not Significantly Impair In Vitro Proteinmentioning

confidence: 99%

Dynamic Interaction of the Sec Translocon with the Chaperone PpiD

Sachelaru

Petriman

Kudva

et al. 2014

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

Genetic Analysis of 15 Protein Folding Factors and Proteases of the Escherichia coli Cell Envelope

Cited by 27 publications

References 73 publications

Salinity-Dependent Impacts of ProQ, Prc, and Spr Deficiencies on Escherichia coli Cell Structure

Salinity-Dependent Impacts of ProQ, Prc, and Spr Deficiencies on Escherichia coli Cell Structure

Protease homolog BepA (YfgC) promotes assembly and degradation of β-barrel membrane proteins in Escherichia coli

Dynamic Interaction of the Sec Translocon with the Chaperone PpiD

Contact Info

Product

Resources

About