An adenosine nucleotide switch controlling the activity of a cell type-specific transcription factor in B. subtilis

Four additional genes in the sigB operon of Bacillus subtilis that control activity of the general stress factor sigma B in response to environmental signals

“…Alper et al (1) have presented in vitro evidence that these homologs form a sensing system which regulates F activity in response to changes in adenosine nucleotide levels. Consistent with this hypothesis, F activity was modestly induced when an uncoupler of oxidative phosphorylation was added to growing cells.…”

“…Also intriguing is the resemblance of the hypothetical orfS product to the SpoIIAA protein of Bacillus licheniformis, with which it shares 25.5% identity in a 94-residue overlap (not shown). In B. subtilis, the 117-residue SpoIIAA protein is required for activation of the sporulation-essential F (1,45), and SpoIIAA is a homolog of RsbV, the positive activator of B (8,29). This open reading frame is separated from the sigB operon by a sequence resembling a factor-independent terminator (⌬G ϭ Ϫ10 kCal; 1 cal ϭ 4.184 J), with a region of dyad symmetry at nt 256 to 274 (indicated by Ͼ) and a run of seven thymidines at nt 275 to 281.…”

Compartmentalized distribution of the proteins controlling the prespore‐specific transcription factor σF of Bacillus subtilis

“…SpoIIAB is an inhibitor or anti-sigma factor of j F , which acts by directly binding to j F (in an interaction that is stimulated by ATP) preventing it from interacting with core RNA polymerase (Duncan & Losick 1993;Min et al 1993;Alper et al 1994;Diederich et al 1994). SpoIIAA is an anti-anti-sigma factor, which can bind to SpoIIAB, thereby freeing j F (Alper et al 1994;Diederich et al 1994;Duncan et al 1996). The interaction between SpoIIAA and SpoIIAB is a complicated one because SpoIIAB is also a kinase which catalyses the phosphorylation of SpoIIAA on a specific serine residue (serine 58), rendering the product (SpoIIAA-P) inactive (Min et al 1993;Alper et al 1994;Diederich et al 1994;Najafi et al 1995;Magnin et al 1996).…”

“…The interaction between SpoIIAA and SpoIIAB is a complicated one because SpoIIAB is also a kinase which catalyses the phosphorylation of SpoIIAA on a specific serine residue (serine 58), rendering the product (SpoIIAA-P) inactive (Min et al 1993;Alper et al 1994;Diederich et al 1994;Najafi et al 1995;Magnin et al 1996). Since ATP stimulates the binding of SpoIIAB to j F and acts as a substrate in the phosphorylation reaction, and ADP stimulates binding of SpoIIAA to SpoIIAB, changes in the levels of these adenosine nucleotides in vivo could provide the signal that regulates the release of j F activity (Alper et al 1994;Diederich et al 1994). However, another gene required for j F activity (spoIIE ) was recently shown to encode a specific phosphatase that can dephosphorylate SpoIIAA-P and thus regenerate pools of active SpoIIAA (Duncan et al 1995;Arigoni et al 1996;Feucht et al 1996).…”

Heat‐shock and general stress response in Bacillus subtilis

“…RsbW requires rather high concentrations of ATP (in the range of several hundred micromolar) in order to phosphorylate RsbV effectively (S. Alper and R. Losick, personal communication). In contrast to the regulation of the activity of the sporulation-specific sigma factor s F , where ATP stimulates the binding of the anti-sigma factor SpoIIAB to s F and ADP favours the binding of SpoIIAB to its anti-anti-sigma factor SpoIIAA (Alper et al, 1994;Diederich et al, 1994), ATP influences the RsbU and RsbX influence the binding preference of RsbW (Völker et al, 1995a). RsbU or a process dependent upon RsbU can stimulate the binding of RsbV to RsbW, a reaction which probably involves changes in the phosphorylation status of RsbV.…”