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

Abstract

A two-dimensional (2-D) gel electrophoresis study of Bacillus subtilis strain 168 identified 20 proteins that are strongly induced in response to phosphate starvation. The induction of nine of these phosphate-starvation-induced (Psi) proteins was dependent on a functional PhoR protein. PhoR is the histidine sensor-kinase component of a phosphate-concentration-sensing twocomponent regulatory system which, together with its partner response regulator PhoP, controls the expression of genes in the Pho regulon. Genes encoding PhoR-dependent Psi proteins are therefore likely to be members of the Pho regulon. SpoOA -P, the response regulator of the signal transduction pathway required for the induction of sporulation, has previously been shown to negatively affect the induction of the Pho regulon by repressing the phoPqahoR operon. The induction pattern of some PhoR-dependent Psi proteins was altered in a spoOA mutant such that their synthesis continued for longer than was found with the wild-type. The most abundant Psi protein, Psil-3, was characterized by N-terminal sequencing of internal peptide fragments and shown to have a high similarity to an Escherichia d i protein which is involved in phosphate uptake during phosphate starvation.

Post-transcriptional regulation of the Bacillus subtilis pst operon encoding a phosphate-specific ABC transporter

“…The size of the prominent mRNA band corresponded to that of the pstS gene. The intensity of 0?9 kb transcript, compared with that of the full-length transcript, is consistent with proteomic studies showing that PstS is the most prominent protein encoded by the operon (Eymann et al, 1996;Antelmann et al, 2000). The transcript patterns obtained with the pstC-and pstA-specific probes (Fig.…”

“…Proteomic analyses indicate that the proteins encoded by the pst operon are present in the cell in very different amounts (Eymann et al, 1996;Antelmann et al, 2000). While PstS (the substrate-binding component) represents the most prominent protein spot in both the cytoplasmic and extracellular proteome fractions, significantly lower amounts of PstBA and PstBB (membrane-associated ATPbinding components of the transporter) were detected exclusively in the cytoplasmic fraction.…”

“…Proteomic analyses of B. subtilis (Eymann et al, 1996;Antelmann et al, 2000) indicate that the most abundant protein induced in response to phosphate starvation is PstS, the lipoprotein substrate-binding component of a high-affinity phosphate transporter belonging to the ABC (ATP-binding cassette) superfamily of transporters (Higgins, 1992;Boos & Lucht, 1996). The genes downstream and in the same operon as pstS are pstC, pstA, pstBA and pstBB (Fig.…”

Influence of Bacillus subtilis phoR on cell wall anionic polymers

“…When the growth of Bacillus subtilis becomes limited by the availability of phosphorus, a programmed series of responses is induced that can ultimately lead to sporulation. Among the earliest of these responses are processes that reduce the cell's requirement for phosphorus, increase its affinity for the uptake of phosphate and lead to the production of extracellular hydrolytic enzymes that allow the cell to recover inorganic phosphate from organic sources such as teichoic acids (Grant, 1979;Eymann et al, 1996). If these conservation and scavenging mechanisms are effective, the developmental pathway leading to sporulation is reversed and the organism resumes vegetative growth.…”

“…subtilis responds to phosphate stress by the coordinated induction of approximately 20 genes (Eymann et al, 1996). Prominent among these are genes of the Pho regulon (Seki et al, 1987;Hulett, 1993;Hulett et al, a two-component, environment-sensing, signal-trans-duction system (Seki et al, 1987(Seki et al, ,1988.…”