Dynamic regulation of extracellular ATP in Escherichia coli

• Published in: Biochemical journal Vol. 474; no. 8; p. 1395
• Main Authors: Alvarez, Cora Lilia, Corradi, Gerardo, Lauri, Natalia, Marginedas-Freixa, Irene, Leal Denis, María Florencia, Enrique, Nicolás, Mate, Sabina María, Milesi, Verónica, Ostuni, Mariano Anibal, Herlax, Vanesa, Schwarzbaum, Pablo Julio
• Format: Journal Article
• Language: English
• Published: England 15.04.2017
• Subjects: Adenosine Triphosphatases - metabolism; Adenosine Triphosphate - metabolism; Animals; Caco-2 Cells; Coculture Techniques; Enterocytes - metabolism; Enterocytes - secretion; Enterocytes - ultrastructure; Escherichia coli - physiology; Escherichia coli - ultrastructure; Escherichia coli Proteins - metabolism; Extracellular Vesicles - metabolism; Extracellular Vesicles - secretion; Extracellular Vesicles - ultrastructure; Host-Pathogen Interactions; Humans; Hydrolysis; Jejunum - metabolism; Jejunum - secretion; Jejunum - ultrastructure; Kinetics; Luminescence; Melitten - metabolism; Microscopy, Electron; Peptides; Phosphoric Monoester Hydrolases - metabolism; Rats, Wistar; extracellular ATP regulation; mastoparan 7; Caco-2 cells; melittin; outer membrane vesicles; Escherichia coli
• ISSN: 1470-8728
• DOI: 10.1042/BCJ20160879

We studied the kinetics of extracellular ATP (ATPe) in and their outer membrane vesicles (OMVs) stimulated with amphipatic peptides melittin (MEL) and mastoparan 7 (MST7). Real-time luminometry was used to measure ATPe kinetics, ATP release, and ATPase activity. The latter was also determined by following [ P]Pi released from [γ- P]ATP. was studied alone, co-incubated with Caco-2 cells, or in rat jejunum segments. In , the addition of [γ- P]ATP led to the uptake and subsequent hydrolysis of ATPe. Exposure to peptides caused an acute 3-fold (MST7) and 7-fold (MEL) increase in [ATPe]. In OMVs, ATPase activity increased linearly with [ATPe] (0.1-1 µM). Exposure to MST7 and MEL enhanced ATP release by 3-7 fold, with similar kinetics to that of bacteria. In Caco-2 cells, the addition of ATP to the apical domain led to a steep [ATPe] increase to a maximum, with subsequent ATPase activity. The addition of bacterial suspensions led to a 6-7 fold increase in [ATPe], followed by an acute decrease. In perfused jejunum segments, exposure to increased luminal ATP 2 fold. ATPe regulation of depends on the balance between ATPase activity and ATP release. This balance can be altered by OMVs, which display their own capacity to regulate ATPe. can activate ATP release from Caco-2 cells and intestinal segments, a response which might lead to intestinal release of ATP from the gut lumen.