Proteomics insights into the Burkholderia cenocepacia phosphorus stress response

Abstract

The Burkholderia cepacia complex is a group of Burkholderia species that are opportunistic pathogens causing high mortality rates in patients with cystic fibrosis. An environmental stress often encountered by these soil-dwelling and pathogenic bacteria is phosphorus limitation, an essential element for cellular processes. Here, we describe cellular and extracellular proteins differentially regulated between phosphate-deplete (0 mM, no added phosphate) and phosphate-replete (1 mM) growth conditions using a comparative proteomics (LC-MS/MS) approach. We observed a total of 128 and 65 unique proteins were downregulated and upregulated respectively, in the B. cenocepacia proteome. Of those downregulated proteins, many have functions in amino acid transport/ metabolism. We have identified 24 upregulated proteins that are directly/indirectly involved in inorganic phosphate or organic phosphorus acquisition. Also, proteins involved in virulence and antimicrobial resistance were differentially regulated, suggesting B. cenocepacia experiences a dramatic shift in metabolism under these stress conditions. Overall, this study provides a baseline for further research into the biology of Burkholderia in response to phosphorus stress.

Phosphorus stress induces the synthesis of novel glycolipids in Pseudomonas aeruginosa that confer protection against a last-resort antibiotic

“…The UniProt proteome for P. aeruginosa strain PAO1 was used for peptide analysis. Further data analysis was carried out using MaxQuant and Perseus software as described previously; peptides without triplicate measures were filtered out [24].…”

Characterization of glyphosate‐resistant Burkholderia anthina and Burkholderia cenocepacia isolates from a commercial Roundup® solution

“…To ensure that the Burkholderia isolates 1CH1 and 2CH1 were experiencing phosphate stress during cultivation without phosphate and with glyphosate, we used alkaline phosphate activity as an indicator of phosphate limitation (Shropshire et al ., 2021). Both Burkholderia isolates showed a significant increase in alkaline phosphatase activity after 2 h of cultivation without phosphate and in medium containing glyphosate (Fig.…”

“…Glyphosate was added as indicated. A modified minimal A medium (Shropshire et al ., 2021) was used to assess phosphate limitation. The medium was composed of Na‐succinate (5.4 g L −1 ), NaCl (200 mg L −1 ), NH 4 Cl (450 mg L −1 ), CaCl 2 (200 mg L −1 ), KCl (200 mg L −1 ), MgCl 2 (450 mg L −1 ) FeCl 2 (10 mg L −1 ), MnCl 2 (10 mg L −1 ) and 10 mM Hepes buffer (pH 7).…”

“…The alkaline phosphate assay to determine whether the bacteria experience phosphate starvation was performed according to Shropshire et al ., (2021). with the following modifications.…”

Burkholderia PglL enzymes are serine preferring oligosaccharidetransferases which target conserved proteins across the Burkholderia genus

“…Although our glycoproteome of B. cenocepacia significantly expands the known number of glycosylation sites from six sites in 23 glycoproteins 29 to 88 sites in 70 glycoproteins, it is important to note these glycosylation events likely still only represent a subset of the complete B. cenocepacia glycoproteome. It is well known that growth under different conditions, such as nutrient limitation 77 and or in the presence of chemical queues 78,79 can dramatically alter the observable proteome of B. cenocepacia. As the growth of B. cenocepacia strains were undertaken under laboratory conditions with growth on rich media, it is possible multiple glycoproteins not expressed under these conditions have been missed.…”