Two-component systems of Corynebacterium glutamicum: deletion analysis and involvement of the PhoS-PhoR system in the phosphate starvation response.
Corynebacterium glutamicum contains genes for 13 two-component signal transduction systems. In order to test for their essentiality and involvement in the adaptive response to phosphate (Pi) starvation, a set of 12 deletion mutants was constructed. One of the mutants was specifically impaired in its ability to grow under Pi limitation, and therefore the genes lacking in this strain were named phoS (encoding the sensor kinase) and phoR (encoding the response regulator). DNA microarray analyses with the C. glutamicum wild type and the DeltaphoRS mutant supported a role for the PhoRS system in the adaptation to Pi starvation. In contrast to the wild type, the DeltaphoRS mutant did not induce the known Pi starvation-inducible (psi) genes within 1 hour after a shift from Pi excess to Pi limitation, except for the pstSCAB operon, which was still partially induced. This indicates an activator function for PhoR and the existence of at least one additional regulator of the pst operon. Primer extension analysis of selected psi genes (pstS, ugpA, phoR, ushA, and nucH) confirmed the microarray data and provided evidence for positive autoregulation of the phoRS genes.
Kocan
Martina
M
Institut für Biotechnologie 1, Forschungszentrum Jülich, D-52425 Jülich, Germany. m.bott@fz-juelich.de.
Schaffer
Steffen
S
Ishige
Takeru
T
Sorger-Herrmann
Ulrike
U
Wendisch
Volker F
VF
Bott
Michael
M
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D048230:Corynebacterium glutamicum / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D003470:Culture Media; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009876:Operon; D010710:Phosphates; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D015398:Signal Transduction
D001426:Bacterial Proteins; D003470:Culture Media; D010710:Phosphates; D012333:RNA, Messenger; D011494:Protein Kinases