Phosphate regulated proteins of Xanthomonas citri subsp. citri: a proteomic approach.
Xanthomonas citri subsp. citri (X. citri) is the causative agent of the citrus canker, a disease that affects several citrus plants in Brazil and across the world. Although many studies have demonstrated the importance of genes for infection and pathogenesis in this bacterium, there are no data related to phosphate uptake and assimilation pathways. To identify the proteins that are involved in the phosphate response, we performed a proteomic analysis of X. citri extracts after growth in three culture media with different phosphate concentrations. Using mass spectrometry and bioinformatics analysis, we showed that X. citri conserved orthologous genes from Pho regulon in Escherichia coli, including the two-component system PhoR/PhoB, ATP binding cassette (ABC transporter) Pst for phosphate uptake, and the alkaline phosphatase PhoA. Analysis performed under phosphate starvation provided evidence of the relevance of the Pst system for phosphate uptake, as well as both periplasmic binding proteins, PhoX and PstS, which were formed in high abundance. The results from this study are the first evidence of the Pho regulon activation in X. citri and bring new insights for studies related to the bacterial metabolism and physiology. Biological significance Using proteomics and bioinformatics analysis we showed for the first time that the phytopathogenic bacterium X. citri conserves a set of proteins that belong to the Pho regulon, which are induced during phosphate starvation. The most relevant in terms of conservation and up-regulation were the periplasmic-binding proteins PstS and PhoX from the ABC transporter PstSBAC for phosphate, the two-component system composed by PhoR/PhoB and the alkaline phosphatase PhoA.
Laboratório Nacional de Biociências - LNBio, Centro de Pesquisas em Energia e Materiais - CNPEM, Campinas, SP, Brazil; Universidade Estadual de Campinas - UNICAMP, Instituto de Biologia, Campinas, SP, Brazil.
Vanessa Rodrigues
VR
Pegos
Laboratório Nacional de Biociências - LNBio, Centro de Pesquisas em Energia e Materiais - CNPEM, Campinas, SP, Brazil.
Jéssica Faria
JF
Nascimento
Laboratório Nacional de Biociências - LNBio, Centro de Pesquisas em Energia e Materiais - CNPEM, Campinas, SP, Brazil.
Tiago José Paschoal
TJ
Sobreira
Laboratório Nacional de Biociências - LNBio, Centro de Pesquisas em Energia e Materiais - CNPEM, Campinas, SP, Brazil.
Bianca Alves
BA
Pauletti
Laboratório Nacional de Biociências - LNBio, Centro de Pesquisas em Energia e Materiais - CNPEM, Campinas, SP, Brazil.
Adriana
A
Paes-Leme
Universidade de São Paulo - USP, Instituto de Ciências Biomédicas II, Departamento de Microbiologia, - São Paulo - SP, Brazil; Laboratório Nacional de Biociências - LNBio, Centro de Pesquisas em Energia e Materiais - CNPEM, Campinas, SP, Brazil. Electronic address: abalan@usp.br.
Andrea
A
Balan
D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D013058:Mass Spectrometry; D028044:Phosphate-Binding Proteins / Q000235:genetics / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D020543:Proteome / Q000235:genetics / Q000378:metabolism; D040901:Proteomics; D018085:Regulon / Q000502:physiology*; D013045:Species Specificity; D014974:Xanthomonas / Q000235:genetics / Q000378:metabolism
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D028044:Phosphate-Binding Proteins; D010710:Phosphates; D020543:Proteome; C061278:PhoB protein, Bacteria; C061279:PhoR protein, Bacteria
ABC transporter; Phosphate regulon; Pst system; Xanthomonas citri subsp. citri