Understanding the Master Regulator

Science's STKE  12 Dec 2006:
Vol. 2006, Issue 365, pp. tw422
DOI: 10.1126/stke.3652006tw422

Bacterial pathogens need to be able to endure rapid and extreme environmental shifts and meanwhile ensure appropriate switches in gene expression. The two-component "master regulator" signaling system constituted by the PhoP regulator protein and the PhoQ Mg2+ sensor is an important virulence regulator for pathogenic bacteria. Shin et al. found that immediately after activation of PhoP and PhoQ, an initial surge in transcription is followed by lower steady-state levels of transcription of target genes. The transcriptional surge was also observed in other two-component systems and may represent a general response that allows organisms to establish a new phenotype immediately in novel conditions.

D. Shin, E.-J. Lee, H. Huang, E. A. Groisman, A positive feedback loop promotes transcription surge that jump-starts Salmonella virulence circuit. Science 314, 1607-1609 (2006). [Abstract] [Full Text]