Sporulation-specific sigma factor sigma 29 of Bacillus subtilis is synthesized from a precursor protein, P31.

Abstract

Evidence is presented that a sporulationessential or factor of Bacillus subtilis, a29, is synthesized as an inactive precursor (P3') and that its activation occurs by a developmentally regulated cleavage of 29 amino acids from the p31 amino terminus. A pulse-chase experiment demonstrated that r29 was derived from a preexisting protein, with appearance of radioactively labeled ar29 paralleling the disappearance of labeled P31. The disappearance of pulse-labeled P31 did not occur when the experiment was done with a B. subtilis strain carrying a mutation in a locus (spollE) GBq) to 25 uCi/ml; then either the cultures were harvested or the label was "chased" by the addition of a 103-fold excess of unlabeled methionine with continued incubation prior to harvesting. Cell extracts were prepared as described (4) and treated overnight at 4°C with anti-o-29 monoclonal antibody (4) in a 0.5-ml reaction mixture containing 10 mM Tris (pH 7.8), 10 mM EDTA, 0.3 mg ofphenylmethylsulfonyl fluoride, 0.1% NaDodSO4, 0.2% deoxycholate, 1% Triton X-100, a concentrated extract from 10 ml of B. subtilis culture, and 20,ug of antibody. Extracts then were incubated in the same reaction buffer with rabbit anti-mouse immunoglobulin for 4 hr, followed by incubation with washed Staphylococcus aureus cells (11)

Evidence that the spoIIM gene of Bacillus subtilis is transcribed by RNA polymerase associated with sigma E

“…Nevertheless, there is growing support for the proposal (14-16, 41) that the mother cell-specific counterpart of (rF is cr-, the product of spoIIGB, the second cistron of the spoIIG operon (75,82). The or-protein is synthesized initially as an inactive precursor, pro-a', which is believed to be processed proteolytically by SpoIIGA to yield the active form of the protein (6,30,37,74). This processing event normally requires the products of both spollE and spoIL4 (9,30,74), and it was previously speculated by three groups (3,4,6,37,73,74,83) to be dependent directly upon the synthesis of a normal sporulation septum.…”

Cell-cell signaling pathway activating a developmental transcription factor in Bacillus subtilis.

“…It is initiated by activation of the r factor in the smaller cell, the forespore (Margolis et al 1991;Partridge et al 1991), which is required for subsequent activation of the cE factor in the larger cell, the mother cell Losick and Stragier 1992). r is synthesized in the predivisional cell (Gholamhoseinian and Piggot 1989) as an inactive larger precursor, pro-tx E (LaBell et al 1987) the product of the spoHGB gene (Stragier et al 1984;Trempy et al 1985a), which is cotranscribed with spolIGA, the gene encoding the putative pro-or E processing enzyme (Stragier et al 1988). SpoIIGA is predicted to be a membrane-bound protein (Stragier et al 1988;Peters and Haldenwang 1991 ) and is also synthesized before septation, suggesting that it is present on both sides of the septum.…”

cse15, cse60, and csk22 are new members of mother-cell-specific sporulation regulons in Bacillus subtilis

“…The cse15 and cse60 promoters are therefore active during the same period of development as E (Fig. 4A and B), and deletion of the E -encoding gene, sigE (32,42), totally prevents cse15 and cse60 expression (Fig. 4A and B).…”

“…The activation of the different sigma factors is itself strongly coupled to specific points in the morphological sequence (45). E , for example, is synthesized in a pro-form in the predivisional cell (32,42), and its proteolytic activation is somehow coupled to the septation process and to the activity of F , a prespore-specific sigma factor (35,44). Conversion of pro-E to its active form, E , which occurs exclusively in the mother cell, inaugurates the program of gene expression in this compartment (19,35,44,68).…”