Dissecting the VanRS signal transduction pathway with specific inhibitors.
The VanRS two-component signal transduction pathway from Enterococcus faecium was reconstituted in vitro from partially purified components and shown to be inhibited by the halophenyl isothiazolone LY-266,400, inhibitor A, a compound shown previously to reduce expression of the AlgR1-AlgR2 two-component signal transduction pathway in Pseudomonas aeruginosa (S. Roychoudhury, N. A. Zielinski, A. J. Ninfa, N. E. Allen, L. N. Jungheim, T. I. Nicas, and A. M. Chakrabarty, Proc. Natl. Acad. Sci. USA 90:965-969, 1993). Inhibitor A attenuates phosphoryl transfer from VanS approximately P to VanR by its action on the ability of VanR to accept. We observed an apparent stimulatory effect of inhibitor A on VanS autophosphorylation which is attributable to the accumulation of VanS approximately P as an intermediate unable to transfer Pi to the inhibited VanR. Thus, inhibitor A acts on the second of two sequential steps which lead to transcriptional activation of the VanHAXYZ gene cluster and the resultant expression of vancomycin resistance.
Ulijasz
A T
AT
Department of Pharmacology, University of Wisconsin Medical School, Madison, Wisconsin 53706, USA.
Weisblum
B
B
D001426:Bacterial Proteins; D017931:DNA Primers; D004352:Drug Resistance, Microbial / Q000235:genetics; D016984:Enterococcus faecium / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D007700:Kinetics; D005810:Multigene Family; D010710:Phosphates / Q000378:metabolism; D010766:Phosphorylation; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014640:Vancomycin / Q000494:pharmacology
D001426:Bacterial Proteins; D017931:DNA Primers; D010710:Phosphates; D014157:Transcription Factors; C073902:VanR protein, bacteria; C073901:VanS protein, Enterococcus; D014640:Vancomycin; D011494:Protein Kinases