title: Cytoplasmic Escherichia coli ADP sugar pyrophosphatase binds to cell membranes in response to extracellular signals as the cell population density increases.
abstract: ADP sugar pyrophosphatase (AspP) is a member of the 'Nudix' (Nucleoside diphosphate linked to some other moiety X) hydrolase family of enzymes that catalyzes the hydrolytic breakdown of ADP-glucose (ADPG) linked to glycogen biosynthesis. In a previous work, we showed that AspP activity is strongly enhanced by both glucose-1,6-bisphosphate and nucleotide-sugars, and by macromolecular crowding. In this work, we show that AspP binds to cell membranes as the bacterial population density increases, c. 30% of the total enzyme remaining membrane associated as glycogen depletes during the stationary phase. This process is not dependent on the stationary transcription factor RpoS, the producer of the bacterial quorum-sensing autoinducer 2 (LuxS), the presence of glycogen granules or glucose availability, but is stimulated by small soluble heat-labile molecule(s) occurring in cell-free spent supernatants of stationary cultures that are acid stabile and base labile. These data further point to AspP as a highly regulated enzyme, and provide a first set of evidences indicating that glycogen metabolism is subjected to regulation by intercellular communication in Escherichia coli.
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Morán-Zorzano
authors.forename: Manuel
authors.initials: M
authors.lastname: Montero
authors.forename: Francisco José
authors.initials: FJ
authors.lastname: Muñoz
authors.forename: Nora
authors.initials: N
authors.lastname: Alonso-Casajús
authors.forename: Alejandro Miguel
authors.initials: AM
authors.lastname: Viale
authors.forename: Gustavo
authors.initials: G
authors.lastname: Eydallin
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Sesma
authors.forename: Edurne
authors.initials: E
authors.lastname: Baroja-Fernández
authors.forename: Javier
authors.initials: J
authors.lastname: Pozueta-Romero
mesh_terms: D000247:Adenosine Diphosphate Sugars / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology / Q000235:genetics; D003593:Cytoplasm / Q000201:enzymology / Q000235:genetics; D004926:Escherichia coli / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D005110:Extracellular Space / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D011485:Protein Binding; D021381:Protein Transport; D011755:Pyrophosphatases / Q000235:genetics / Q000378:metabolism*
chemical_list: D000247:Adenosine Diphosphate Sugars; D001426:Bacterial Proteins; D011755:Pyrophosphatases; C019620:ADPribose pyrophosphatase