title: SKPDT is a signaling peptide that stimulates sporulation and cry1Aa expression in Bacillus thuringiensis but not in Bacillus subtilis.
abstract: We have identified and characterized in the supernatant of the transition phase of Bacillus thuringiensis var. kurstaki the peptide SKPDT. This peptide was previously identified by in silico analysis by Pottathil and Lazazzera (Front Biosci 8:32-45 2003) as a putative signaling peptide (NprRB) of the Phr family in B. thuringiensis. The chemically synthesized NprRB did not affect the growth kinetics of B. thuringiensis var. kurstaki but stimulated the sporulation, spore release, and transcription of cry1Aa when added to cultures during the transition phase. In fact, when the peptide (100 nM) was added to a culture in transition phase, the transcription of cry1Aa was stimulated almost threefold, mainly from the late promoter BtII, which requires the late-stage sporulation-specific transcription factor sigma (K). On the other hand, NprRB did not have any effect on B. subtilis. Thus, SKPDT seems to be a signaling peptide specific for B. thuringiensis.
authors.affiliation: Centro de Investigación en Alimentación y Desarrollo A.C., P.O. Box 1735, Km 0.6 Carretera a la Victoria, 83000, Hermosillo, Sonora, México.
authors.forename: Angel E
authors.initials: AE
authors.lastname: Aceves-Diez
authors.forename: Refugio
authors.initials: R
authors.lastname: Robles-Burgueño
authors.forename: Mayra
authors.initials: M
authors.lastname: de la Torre
mesh_terms: D001412:Bacillus subtilis / Q000502:physiology*; D001413:Bacillus thuringiensis / Q000502:physiology*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000378:metabolism*; D001427:Bacterial Toxins / Q000378:metabolism*; D004731:Endotoxins / Q000378:metabolism*; D006460:Hemolysin Proteins / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins / Q000138:chemical synthesis / Q000502:physiology*; D013045:Species Specificity; D013171:Spores, Bacterial / Q000254:growth & development
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D036341:Intercellular Signaling Peptides and Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis