TY - JOUR
T1 - Transcriptional activity of Pseudomonas aeruginosa fhp promoter is dependent on two regulators in addition to FhpR
AU - Koskenkorva, Taija
AU - Aro-Kärkkäinen, Niina
AU - Bachmann, Daniel
AU - Arai, Hiroyuki
AU - Frey, Alexander D.
AU - Kallio, Pauli T.
PY - 2008/4
Y1 - 2008/4
N2 - The regulation of flavohemoglobin expression is complex and depending on its host organism requires a wide variety of different transcriptional regulators. In Pseudomonas aeruginosa, the flavohemoglobin (Fhp) and its cognate regulator FhpR form an NO-sensing and detoxifying system regulated by their common bidirectional promoter P fhp/P fhpR. The intergenic fhp-fhpR region of P. aeruginosa PAO1 was used as a bait to isolate proteins affecting the transcription of fhp and fhpR. In addition to the FhpR, we identified two previously uncharacterized P. aeruginosa proteins, PA0779 and PA3697. Both PA0779 and PA3697 were found to be essential for NO3 - and NO2 - induced P fhp activity under aerobic and low-oxygen conditions, and needed for the full function of P fhp/P fhpR as NO responsive regulatory circuit under aerobic conditions. In addition, we show that the transcriptional activity of P fhpR is highly inducible upon addition of SNP under aerobic conditions, but not by NO3 -, NO2 - or under low-oxygen conditions, supporting the findings that FhpR is not the only factor affecting flavohemoglobin expression in P. aeruginosa.
AB - The regulation of flavohemoglobin expression is complex and depending on its host organism requires a wide variety of different transcriptional regulators. In Pseudomonas aeruginosa, the flavohemoglobin (Fhp) and its cognate regulator FhpR form an NO-sensing and detoxifying system regulated by their common bidirectional promoter P fhp/P fhpR. The intergenic fhp-fhpR region of P. aeruginosa PAO1 was used as a bait to isolate proteins affecting the transcription of fhp and fhpR. In addition to the FhpR, we identified two previously uncharacterized P. aeruginosa proteins, PA0779 and PA3697. Both PA0779 and PA3697 were found to be essential for NO3 - and NO2 - induced P fhp activity under aerobic and low-oxygen conditions, and needed for the full function of P fhp/P fhpR as NO responsive regulatory circuit under aerobic conditions. In addition, we show that the transcriptional activity of P fhpR is highly inducible upon addition of SNP under aerobic conditions, but not by NO3 -, NO2 - or under low-oxygen conditions, supporting the findings that FhpR is not the only factor affecting flavohemoglobin expression in P. aeruginosa.
KW - fhp
KW - fhpR
KW - Flavohemoglobin
KW - P. aeruginosa
KW - PA0779
KW - PA3697
KW - Transcriptional regulation
UR - http://www.scopus.com/inward/record.url?scp=43349102403&partnerID=8YFLogxK
U2 - 10.1007/s00203-007-0329-3
DO - 10.1007/s00203-007-0329-3
M3 - Article
C2 - 18043907
AN - SCOPUS:43349102403
VL - 189
SP - 385
EP - 396
JO - Archives of Microbiology
JF - Archives of Microbiology
SN - 0302-8933
IS - 4
ER -