Separate promoters direct expression of phoAIII, a member of the Bacillus subtilis alkaline phosphatase multigene family, during phosphate starvation and sporulation

Abstract

Alkaline phosphatase (APase) expression can be induced in Bacillus subtilis by phosphate starvation or by sporulation. We have recently shown that there are multiple APase structural genes contributing to the total alkaline phosphatase expression in B. subtilis. The expression of the alkaline phosphatase III gene (phoAIII) was analysed under both phosphate-starvation induction and sporulation induction conditions. phoAII is transcribed from two promoter regions, PV and PS. The PV promoter initiated transcription 37 bp before the translation initiation codon and was used to transcribe phoAIII during phosphate-starvation induction in vegetative cells. The PS promoter initiated transcription 119 bp before the translation initiation codon and was used during sporulation induction. Genes which have previously been shown to affect total vegatative APase, pho regulon genes phoP, phoR and phoS, affected expression of phoAIII during phosphate starvation. Genes known to affect expression of total sporulation APase, i.e. spoIIA, spoIIG and spoIIE, affected phoAIII expression during sporulation induction. Our data show that one member of the APase multigene family, phoAIII, contributes to the total APase expression both during phosphate-starvation induction and sporulation induction, and that the mechanism of regulation includes two promoters, each requiring different regulatory genes.

Sites internal to the coding regions of phoA and pstS bind PhoP and are required for full promoter activity

“…The repetitive pattern of each pair of TTAACA-like sequences -but not the sequences themselves -is similar to that of the E. coli Pho box (Kimura et al, 1989;Wanner, 1996) and has been proposed to be the putative B. subtilis Pho box (Qi et al, 1997). DNase I footprinting assays using the phoB, phoA and pstS promoters demonstrate that these repetitive sequences are bound by PhoP (Liu and Hulett, 1997) and are essential for promoter activity (Chesnut, 1991;this work). This is similar to the results obtained from E. coli in which deletion of one or two Pho boxes in the pstS promoter dramatically decreases or eliminates the promoter activity (Kimura et al, 1989).…”

“…This promoter contains two tandem promoters, the P s and P v promoters, which are responsible for sporulation APase and phosphate starvation inducible APase production respectively (Chesnut et al, 1991). We have demonstrated recently that PhoP binds exclusively within the P v region of the phoB tandem promoters in both phosphorylated and unphosphorylated forms, although phosphorylated PhoP (PhoPϳP) binds to the phoB promoter more efficiently (Liu and Hulett, 1997).…”

“…The inorganic phosphate produced in this process is then transferred into the cell by an efficient high-affinity phosphate transport system (Eymann et al, 1996;Qi et al, 1997). Some of the genes that are involved in this process, the Pho regulon genes, have been cloned, and their promoter activities have been found to be regulated by two regulatory genes, phoP and phoR, under phosphate starvation conditions Hulett et al, 1990;1994a,b;Chesnut et al, 1991;Eder et al, 1996;Qi et al, 1997).…”

Phosphate-starvation-inducible proteins in Bacillus subtilis: a two-dimensional gel electrophoresis study

“…B. stlbti1i.r has a multi-gene family for the production of at least four APases (Chesnut e t al., 1991;Hulett et al, 1990Hulett et al, , 1991. The genes for two APases have been mapped and sequenced.…”

Substrate analysis and molecular cloning of the extracellular alkaline phosphatase of Streptomyces griseus The GenBank accession number for the sequence reported in this paper is AJ278740.

“…In spite of its relative abundance in nature, phosphate is sometimes a growth-limiting factor for soil micro-organisms because much of its natural supply occurs as insoluble salts. To cope with phosphate limitation, most bacteria (Au et al, 1991 ;Pond et al, 1989), Archaea (Goldman et al, 1990), yeasts and fungi (Furukawa et al, 1987) have extracellular phosphatases that act as scavengers of phosphate ; these organisms show very sensitive control mechanisms for the regulation of genes involved in phosphate utilization (Anba et al, 1990 ;Chenust et al, 1991 ;Lee et al, 1989). Abbreviations : AP, alkaline phosphatase ; PNPP, p-nitrophenyl phosphate ; X-phosphate, 5-bromo-4-chloro-3-indolyl phosphate.…”