Dataset Information

Quantitative proteomic analysis of the response of Pseudomonas aeruginosa to gallium maltolate exposure

ABSTRACT: The semi-metallic element gallium was initially introduced therapeutically as a diagnostic tool for the detection of cancerous tissue and was subsequently incorporated into a number of gallium-based anticancer agents. Gallium-based drugs have since been repurposed as antibacterial therapies and have shown significant potential as an alternative treatment option against resistant pathogens. The activity of gallium (Ga3+) is a result of its chemical similarity to ferric iron (Fe3+) and substitution into iron-dependent pathways. Gallium is incapable of reducing to the 2+ form in typical physiological environments and therefore inhibits iron metabolism vital for bacterial growth. Gallium maltolate (GaM) is an enhanced, novel formulation of gallium, consisting of a central gallium cation coordinated to three maltolate ligands, [Ga(Maltol-1H)3]. This study implemented a label-free quantitative proteomic approach to observe the effect of GaM on the opportunistic pathogen Pseudomonas aeruginosa. Analysis of the changes of the P. aeruginosa proteome in response to GaM exposure revealed how inadequate supplies of iron within the cell may explain the increase in abundance of proteins involved in iron acquisition and storage. A key finding of this study however, was the decreased abundance of proteins associated with quorum-sensing and swarming motility. These processes are a fundamental component of bacterial virulence and dissemination and hence explain a potential role of GaM in the treatment of P. aeruginosa infection.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Galleria Mellonella

SUBMITTER: Magdalena Piatek

LAB HEAD: Profesor Kevin Kavanagh

PROVIDER: PXD019265 | Pride | 2022-06-27

REPOSITORIES: Pride

ACCESS DATA

Dataset's files

Source:

Items per page:

1 - 5 of 13

Similar Datasets

Project description:The airways of cystic fibrosis patients are chronically colonized by a diverse range of microbial pathogens, the composition of which changes throughout life Alteration to the pulmonary environment caused by inter-microbial interactions and pathogen-host interactions influence the type of microbes that can engage in sustained infection. The opportunistic bacterial pathogen Pseudomonas aeruginosa is the primary cause of morbidity and mortality amongst individuals with cystic fibrosis and it is estimated that 60 – 80 % of cystic fibrosis patients experience chronic P. aeruginosa infection by the age of 20 years Aspergillus fumigatus is the most prevalent fungal pathogen isolated from cystic fibrosis airways, affecting up to 58% of patients. It is the causative agent of allergic bronchopulmonary aspergillosis (ABPA), a hypersensitivity disorder resulting from the inhalation of fungal conidia. Although co-colonization of the cystic fibrosis airways by P. aeruginosa and A. fumigatus is rare (3.1 – 15.8 %) disease prognosis is poor when both are present. However, sequential infection is more common. It has recently been suggested that A. fumigatus is more prevalent in juvenile cystic fibrosis patients that has been initially reported due to inconsistencies in the culture methods used to detect A. fumigatus. Despite the prevalence and persistence of A. fumigatus, P. aeruginosa predominates as the primary pathogen in the cystic fibrosis lung, suggesting that interactions with other pathogens such as A. fumigatus may influence the pathogenicity of P. aeruginosa by altering its virulence. We report here an investigation of the effect of culturing P. aeruginosa in the presence of A. fumigatus by measuring differences in growth rate and the overall proteome of the bacteria. It was hypothesized that A. fumigatus creates an environment that promotes a metabolic-driven increase in P. aeruginosa that results in it outcompeting the fungus. The molecular basis of this increased proliferation was investigated further using Label-free quantitative (LFQ) proteomics to characterise the proteome changes in P. aeruginosa when exposed to the supernatant of i) A. fumigatus alone ii) the supernatant of an A. fumigatus/P. aeruginosa co-culture and iii) P. aeruginosa alone. LFQ proteomics involves the simultaneous identification and quantification of thousands of proteins (the ultimate determinants of phenotype) from a single sample has recently been employed to characterise the P. aeruginosa proteome in response to iron limiting conditions, resolving how how the bacteria survives and proliferates in such environments.

Project description:Membrane protein and phospholipid (PL) compositions change in response to environmental cues and during infections. Covalent modification (e.g., unsaturation and cyclopropanation) and remodeling the acyl chain length of PLs is an important bacterial adaptation mechanism. However, little is known about which bacterial pathways are regulated in response to the alteration of PL composition. Here, we show that P. aeruginosa PlaF, which modulates membrane PL composition, is important for biofilm biogenesis, and we performed whole-cell quantitative proteomics of P. aeruginosa wild-type and ∆plaF biofilms to identify pathways regulated by PlaF. The results revealed profound alterations in the abundance of 14 two-component systems (TCS), including the PprA-PprB, which controls the transition to biofilm. Activation of PprA-the PprB system observed by proteomics was confirmed by mRNA quantification. Furthermore, we have observed a unique phosphorylation pattern of transcriptional regulators, transporters and metabolic enzymes, and differential production of nine proteases in ∆plaF, indicating that PlaF-mediated virulence adaptation involves complex transcriptional and post-transcriptional regulation. Moreover, proteomics revealed that the pyoverdin-mediated iron uptake pathway proteins were depleted in ∆plaF, which agrees with decreased concentrations of extracellular pyoverdine and intracellular iron in ∆plaF and is likely responsible for its prolonged lag phase due to reduced iron uptake. Conversely, the accumulation of proteins from alternative iron-uptake systems in ∆plaF suggests that PlaF may function as a switch between different iron-acquisition pathways. The observation that ∆plaF accumulates PL-acyl chain modifying enzymes and PlsX, an initiator of de novo PL synthesis, reveals novel insights into the relationship between degradation, covalent modification and biosynthesis of PLs for membrane homeostasis. Although the precise mechanism by which PlaF simultaneously affects multiple pathways remains to be elucidated, we suggest that PlaF-catalyzed degradation of PLs is a signal which is amplified by proteins of TCS, phosphorylation and proteolytic degradation systems to elicit the global adaptive response in P. aeruginosa.

			Action	DRS
	Magda_1.raw	Raw
	Magda_10.raw	Raw
	Magda_11.raw	Raw
	Magda_12.raw	Raw
	Magda_2.raw	Raw

Dataset Information

Quantitative proteomic analysis of the response of Pseudomonas aeruginosa to gallium maltolate exposure

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets