Gene-expression Analysis of Acidic pH Shock Effects on Two-component Systems in Streptomyces coelicolor

In this study, transcriptional analyses by using reverse transcription-polymerase chain reaction (RT-PCR), DNA chip, and quantitative real time-PCR were performed to investigate effects of acidic pH shock on two-component systems in Streptomyces coelicolor A3(2). Two-component systems of cseC/cseB and vanS/vanR, known to be closely linked with self-protection against cell wall hydrolysis caused by external stimuli were upregulated by the pH shock. The chiS/chiR, afsQ2/afsQ1, ecrA2/ecrA1, bldM, ramC/ramR, and ragK/ragR known to be positively associated with the initiation of secondary metabolism were also upregulated. The cutS/cutR known to be negatively related to the secondary metabolism was, however, slightly downregulated. Upregulation or downregulation by the acidic pH shock of these two-component regulator systems might have contributed in a concerted manner to the enhancement of secondary metabolite production, at least, in this particular case of actinorhodin production in S. coelicolor A3(2). (C) KSBB