Proteomics analysis reveals that CirA in Aeromonas hydrophila is involved in nutrient uptake

Abstract

The colicin I receptor (CirA) is a well‐studied outer membrane protein that has been reported to play important roles in antibiotic resistance, virulence, and iron homeostasis, although its exact physiological roles require further investigation. In this study, differentially expressed proteins between the ΔahcirA and wild‐type (WT) strains of Aeromonas hydrophila were compared using quantitative proteomics. Bioinformatics analysis revealed that the expression of peptide, histidine, and arginine ATP‐binding cassette (ABC) transporter system‐related proteins was significantly higher in the ΔahcirA strain. Subsequent growth assays revealed that ΔahcirA grew slower than the WT strain in nutrient‐limited medium when supplemented with dipeptide, histidine, and arginine as the carbon source. Far‐western blot analysis further confirmed that AhCirA can directly bind to histidine/arginine and dipeptide small‐molecule substrates in addition to their periplasmic‐binding proteins, AhDppA and AhHisJ, respectively. These results indicate that AhCirA may play an important role in the uptake of amino acids and peptides as a channel‐forming porin while also directly interacting with ABC transporters to transport nutrient substances into the plasma membrane. Overall, this study demonstrates that AhCirA is a multifunctional protein in A. hydrophila and extends our understanding of known nutrient transport mechanisms among bacteria.

Unveiling the antibacterial mechanism of resveratrol against Aeromonas hydrophila through proteomics analysis

“…The digested peptides were resuspended in 0.1% formic acid (FA) and 2% acetonitrile (ACN) solution, and then the samples were separated using the EASY-nano-LC chromatographic system (Thermo Scientific Inc., Waltham, MA, USA) with identical parameters as previously described ( Song et al., 2023 ). In brief, peptides were separated using solvent gradient chromatography with binary-mobile phase system of buffer A (2% ACN and 0.1% FA) and buffer B (98% ACN and 0.1% FA) as follows: 0-18 min, 6-12% B; 18-77 min, 12-20% B; 77-109 min, 20-32% B; 109-110 min, 32-90% B; 111-120 min, 90% B hold.…”

Unveiling a Virulence-Regulating Mechanism in Aeromonas hydrophila: a Quantitative Exoproteomic Analysis of an AraC-Like Protein

“…The swimming and swarming agar plates were prepared using LB medium containing 0.3% and 0.6% agar powder, respectively ( 14 ). A single clone of bacterial strains was stabbed and point inoculated on the swimming and swarming agar plates and incubated at 30°C for 6 h and 12 h, respectively.…”