The σ(F)-specific anti-sigma factor RsfA is one of the protein kinases that phosphorylates the pleiotropic anti-anti-sigma factor BldG in Streptomyces coelicolor A3(2).
The anti-anti-sigma factor BldG has a role in the morphological differentiation and antibiotic production of Streptomyces coelicolor A3(2). Together with the anti-sigma factor UshX it is involved in the "partner-switching"-like activation of the sigma factor σ(H) that has a dual role in the osmotic stress response and morphological differentiation in S. coelicolor A3(2). Although BldG is phosphorylated in vivo in S. coelicolor, neither of the interacting anti-sigma factors UshX and ApgA is found to phosphorylate it. By using a combination of several approaches, we demonstrated a direct interaction between BldG and the anti-sigma factor RsfA, which has been previously shown to regulate antibiotic production and morphological differentiation in S. coelicolor and to specifically interact with the sporulation-specific sigma factor σ(F). RsfA phosphorylates BldG in vitro, demonstrating that RsfA is a specific kinase for BldG and negatively regulates its activity. However, another interacting anti-anti-sigma factor homolog, SCO0869, was not phosphorylated by RsfA. Transcriptional analyses of rsfA revealed a single promoter, the activity of which was repressed by osmotic stress and decreased during differentiation. These data suggested that BldG has a pleiotropic role in the regulation of at least two sigma factors, σ(H) and σ(F), in S. coelicolor.
Institute of Molecular Biology, Slovak Academy of Sciences, 845 51 Bratislava, Slovak Republic.
Erik
E
Mingyar
Institute of Molecular Biology, Slovak Academy of Sciences, 845 51 Bratislava, Slovak Republic.
Beatrica
B
Sevcikova
Institute of Molecular Biology, Slovak Academy of Sciences, 845 51 Bratislava, Slovak Republic.
Bronislava
B
Rezuchova
Institute of Molecular Biology, Slovak Academy of Sciences, 845 51 Bratislava, Slovak Republic.
Dagmar
D
Homerova
Institute of Molecular Biology, Slovak Academy of Sciences, 845 51 Bratislava, Slovak Republic.
Renata
R
Novakova
Institute of Molecular Biology, Slovak Academy of Sciences, 845 51 Bratislava, Slovak Republic. Electronic address: jan.kormanec@savba.sk.
Jan
J
Kormanec
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D005798:Genes, Bacterial; D008954:Models, Biological; D008969:Molecular Sequence Data; D009997:Osmotic Pressure; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D054730:Protein Interaction Domains and Motifs; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D012808:Sigma Factor / Q000037:antagonists & inhibitors*; D048372:Streptomyces coelicolor / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
D001426:Bacterial Proteins; C064971:FliA protein, Bacteria; D012808:Sigma Factor; D011494:Protein Kinases
Anti-sigma factor; Partner-switching mechanism; Phosphorylation; Promoter; S1-nuclease mapping; Sigma factor