Aceves-Diez Angel E, Robles-Burgueño Refugio, de la Torre Mayra
Centro de Investigación en Alimentación y Desarrollo A.C., P.O. Box 1735, Km 0.6 Carretera a la Victoria, 83000, Hermosillo, Sonora, México.
Appl Microbiol Biotechnol. 2007 Aug;76(1):203-9. doi: 10.1007/s00253-007-0982-0. Epub 2007 May 8.
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.
我们已在苏云金芽孢杆菌库尔斯塔克变种过渡阶段的上清液中鉴定并表征了肽SKPDT。该肽先前由Pottathil和Lazazzera通过计算机分析（《生物前沿》8:32 - 45，2003年）鉴定为苏云金芽孢杆菌中Phr家族的一种假定信号肽（NprRB）。化学合成的NprRB不影响苏云金芽孢杆菌库尔斯塔克变种的生长动力学，但在过渡阶段添加到培养物中时会刺激cry1Aa的芽孢形成、孢子释放和转录。实际上，当将该肽（100 nM）添加到处于过渡阶段的培养物中时，cry1Aa的转录受到近三倍的刺激，主要来自晚期启动子BtII，该启动子需要晚期芽孢形成特异性转录因子sigma（K）。另一方面，NprRB对枯草芽孢杆菌没有任何影响。因此，SKPDT似乎是苏云金芽孢杆菌特有的信号肽。
