title: Detection of the response regulator AgrA in the cytosolic fraction of Staphylococcus aureus by monoclonal antibodies.
abstract: The expression of many virulence genes in Staphylococcus aureus is controlled by a regulatory RNA molecule, RNAIII, which is encoded by the agr locus. Transcription RNAIII requires the activity of the agrA, B, C and D genes, which code for components of a quorum sensing signal transduction system. In this report we describe the overexpression and purification of the response regulator, AgrA. Monoclonal antibodies were produced and used to detect AgrA in the cytosolic fraction of S. aureus cells. Purified AgrA did not bind to the RNAIII promoter region in a DNA mobility shift experiment. This confirms previous results obtained with protein extracts from agr+ and agr- cells.
authors.affiliation: Microbiology and Tumorbiology Center, Karolinska Institutet, Stockholm, Sweden. eva.morfeldt@mtc.ki.se
authors.forename: E
authors.initials: E
authors.lastname: Morfeldt
authors.forename: I
authors.initials: I
authors.lastname: Panova-Sapundjieva
authors.forename: B
authors.initials: B
authors.lastname: Gustafsson
authors.forename: S
authors.initials: S
authors.lastname: Arvidson
mesh_terms: D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D003001:Cloning, Molecular; D003600:Cytosol / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D016372:RNA, Antisense / Q000235:genetics; D012329:RNA, Bacterial / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D015398:Signal Transduction; D013211:Staphylococcus aureus / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D014774:Virulence / Q000235:genetics
chemical_list: C095698:Agr protein, Staphylococcus aureus; D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins; D017931:DNA Primers; D016372:RNA, Antisense; D012329:RNA, Bacterial; C096035:RNAIII, Staphylococcus aureus; D011994:Recombinant Proteins; D015534:Trans-Activators; D014157:Transcription Factors