Ultra-Performance Liquid Chromatography/Mass Spectrometry for the Detection and Quantification of Diffusible Signal Factor (DSF) Family Quorum-Sensing Signals

Abstract

Molecules of the diffusible signal factor (DSF) family represent a class of widely conserved quorum-sensing signals used by many Gram-negative bacterial pathogens. The measurement of DSF family signals is essential for understanding their biological roles, signaling pathway, and regulatory network. We are presenting here methods for extraction and purification of DSF family signals from culture supernatants, and further quantification of members of DSF family signals using an ultra-performance liquid chromatographic system (UPLC) coupled with an accurate time-of-flight mass spectrometry (TOF-MS) analysis.

Dual Regulatory Role Exerted by Cyclic Dimeric GMP To Control FsnR-Mediated Bacterial Swimming

“…The RR accepts the phosphoryl group through the conserved Asp residue within the REC domain, and performs downstream regulation through its output domain ( 24 , 25 ). The phosphodiesterase activity of RavR, a GGDEF-EAL domain-containing protein, is activated by phosphorylation performed by its cognate HKs RavA and RavS and is putatively stimulated by a low-oxygen tension signal ( 26 , 27 ), while that of RpfG, an HD-GYP domain-containing protein, is stimulated through phosphorylation by its cognate HK RpfC in response to the quorum-sensing (QS) signal, diffusible signal factor (DSF) ( 28 , 29 ). Both RavR and RpfG degrade c-di-GMP to release its inhibition of the activity of the global transcription factor Clp, which binds the promoter and activates the expression of fleQ in X. campestris ( 30 , 31 ).…”

The Plant Defense Signal Salicylic Acid Activates the RpfB-Dependent Quorum Sensing Signal Turnover via Altering the Culture and Cytoplasmic pH in the Phytopathogen Xanthomonas campestris

“…Extraction and quantitative analysis of DSF and BDSF in Xanthomonas campestris pv. campestris cultures were performed following previously described methods ( 55 ). Briefly, 20 mL of liquid cultures were collected for each strain.…”

Tapping into Plant–Microbiome Interactions through the Lens of Multi-Omics Techniques

“…The sensitivity of the instrument is controlled by the column, MS technique, and the analyzer used [ 149 ]. The UPLC-MS technique has been shown to be a platform for hyphenated microseparation for metabolomic analysis of teas [ 150 ] and offers unique advantages in the extraction and purification of the diffusible signal factor family used as quorum-sensing signals in rhizosphere colonization [ 151 ].…”