title: The response regulator PhoP4 is required for late developmental events in Myxococcus xanthus.
abstract: Phosphate regulation is complex in the developmental prokaryote Myxococcus xanthus, and requires at least four two-component systems (TCSs). Here, the identification and characterization of a member of one TCS, designated PhoP4, is reported. phoP4 insertion and in-frame deletion strains caused spore viability to be decreased by nearly two orders of magnitude, and reduced all three development-specific phosphatase activities by 80-90 % under phosphate-limiting conditions. Microarray and quantitative PCR analyses demonstrated that PhoP4 is also required for appropriate expression of the predicted pstSCAB-phoU operon of inorganic phosphate assimilation genes. Unlike the case for the other three M. xanthus Pho TCSs, the chromosomal region around phoP4 does not contain a partner histidine kinase gene. Yeast two-hybrid analyses reveal that PhoP4 interacts reciprocally with PhoR2, the histidine kinase of the Pho2 TCS; however, the existence of certain phenotypic differences between phoP4 and phoR2 mutants suggests that PhoP4 interacts with another, as-yet unidentified, histidine kinase.
authors.affiliation: Section of Microbiology and Center for Genetics and Development, 268 Briggs Hall, University of California, Davis, CA 95616, USA.
authors.forename: Vinh D
authors.initials: VD
authors.lastname: Pham
authors.affiliation: Section of Microbiology and Center for Genetics and Development, 268 Briggs Hall, University of California, Davis, CA 95616, USA.
authors.forename: Conrad W
authors.initials: CW
authors.lastname: Shebelut
authors.affiliation: Section of Microbiology and Center for Genetics and Development, 268 Briggs Hall, University of California, Davis, CA 95616, USA.
authors.forename: Ivy R
authors.initials: IR
authors.lastname: Jose
authors.affiliation: Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: David A
authors.initials: DA
authors.lastname: Hodgson
authors.affiliation: Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: David E
authors.initials: DE
authors.lastname: Whitworth
authors.affiliation: Section of Microbiology and Center for Genetics and Development, 268 Briggs Hall, University of California, Davis, CA 95616, USA.
authors.forename: Mitchell
authors.initials: M
authors.lastname: Singer
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D009154:Mutation; D016941:Myxococcus xanthus / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010710:Phosphates / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D020798:Two-Hybrid System Techniques
chemical_list: D001426:Bacterial Proteins; D010710:Phosphates; C061064:PhoP protein, Bacteria; D010744:Phosphoric Monoester Hydrolases