title: Peptide and amino acid metabolism is controlled by an OmpR-family response regulator in Lactobacillus casei.
abstract: A Lactobacillus casei BL23 strain defective in an OmpR-family response regulator encoded by LCABL_18980 (PrcR, RR11), showed enhanced proteolytic activity caused by overexpression of the gene encoding the proteinase PrtP. Transcriptomic analysis revealed that, in addition to prtP expression, PrcR regulates genes encoding peptide and amino acid transporters, intracellular peptidases and amino acid biosynthetic pathways, among others. Binding of PrcR to twelve promoter regions of both upregulated and downregulated genes, including its own promoter, was demonstrated by electrophoretic mobility shift assays showing that PrcR can act as a transcriptional repressor or activator. Phosphorylation of PrcR increased its DNA binding activity and this effect was abolished after replacement of the phosphorylatable residue Asp-52 by alanine. Comparison of the transcript levels in cells grown in the presence or absence of tryptone in the growth medium revealed that PrcR activity responded to the presence of a complex amino acid source in the growth medium. We conclude that the PrcR plays a major role in the control of the peptide and amino acid metabolism in L. casei BL23. Orthologous prcR genes are present in most members of the Lactobacillaceae and Leuconostocaceae families. We hypothesize that they play a similar role in these bacterial groups.
authors.affiliation: Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), C/Agustín Escardino Benlloch 7, 46980, Paterna, Valencia, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Alcántara
authors.affiliation: Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), C/Agustín Escardino Benlloch 7, 46980, Paterna, Valencia, Spain.
authors.forename: Christine
authors.initials: C
authors.lastname: Bäuerl
authors.affiliation: Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), C/Agustín Escardino Benlloch 7, 46980, Paterna, Valencia, Spain.
authors.forename: Ainhoa
authors.initials: A
authors.lastname: Revilla-Guarinos
authors.affiliation: Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), C/Agustín Escardino Benlloch 7, 46980, Paterna, Valencia, Spain.
authors.forename: Gaspar
authors.initials: G
authors.lastname: Pérez-Martínez
authors.affiliation: Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), C/Agustín Escardino Benlloch 7, 46980, Paterna, Valencia, Spain.
authors.forename: Vicente
authors.initials: V
authors.lastname: Monedero
authors.affiliation: Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), C/Agustín Escardino Benlloch 7, 46980, Paterna, Valencia, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Zúñiga
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D005516:Food Microbiology; D015964:Gene Expression Regulation, Bacterial; D023061:Gene Order; D007780:Lacticaseibacillus casei / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D008892:Milk / Q000382:microbiology; D005810:Multigene Family; D009154:Mutation; D009876:Operon; D010455:Peptides / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D018085:Regulon
chemical_list: D000596:Amino Acids; D010455:Peptides