Role of PhoU in phosphate transport and alkaline phosphatase regulation.
The negative regulatory function of PhoU in alkaline phosphatase (AP) was suggested by the behavior of K10 phoU35 carrying a missense mutation whose product was detected by immunoblotting. To define more clearly the regulatory function of this protein for the synthesis of AP, we constructed a null mutation. The constitutive synthesis of AP in this phoU deletion strain confirmed the negative role of PhoU. However, the expression of the PhoU protein from an isopropyl-beta-D-thiogalactopyranoside-inducible promoter had no effect on the repression of AP synthesis. Furthermore, the involvement of PhoU in free-Pi uptake was demonstrated. These results provide evidence that PhoU participates in Pi transport and in the regulatory role of the phosphate-specific transport system.
Muda
M
M
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
Rao
N N
NN
Torriani
A
A
D000469:Alkaline Phosphatase / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport / Q000235:genetics; D015139:Blotting, Southern; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004790:Enzyme Induction / Q000235:genetics; D029968:Escherichia coli Proteins; D005816:Genetic Complementation Test; D015151:Immunoblotting; D007700:Kinetics; D026901:Membrane Transport Proteins; D010710:Phosphates / Q000378:metabolism*; D010957:Plasmids; D014157:Transcription Factors
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D010710:Phosphates; D014157:Transcription Factors; C050770:phoU protein, E coli; D000469:Alkaline Phosphatase