Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Américo Vespucio 49, E-41092 Seville, Spain.
Lehrstuhl für Mikrobiologie/Organismische Interaktionen, Universität Tübingen, Auf der Morgenstelle 28, D-72076 Tübingen, Germany.
FEBS Lett. 2014 May 2;588(9):1787-94. doi: 10.1016/j.febslet.2014.03.039. Epub 2014 Mar 28.
In Anabaena, the pipX gene is induced in the cells differentiating into heterocysts, being the PipX factor required for full expression of late heterocyst-specific genes. Here we show that PipX has a positive effect on in vitro binding of the transcription factor NtcA to DNA, as well as on transcript production, in different NtcA-dependent promoters. We found that the cox3 operon, encoding a heterocyst-specific terminal respiratory oxidase, is expressed from three nitrogen-regulated promoters to which NtcA binds. At the three sites, NtcA binding is potentiated by PipX. Thus, PipX has a direct effect on gene expression influencing the activity of NtcA.
在鱼腥藻中，pipX 基因在分化为异形胞的细胞中被诱导，PipX 因子是充分表达晚期异形胞特异性基因所必需的。在这里，我们表明 PipX 对转录因子 NtcA 在体外与 DNA 的结合以及不同 NtcA 依赖性启动子中的转录产物的产生有积极影响。我们发现，cox3 操纵子编码一种异形胞特异性末端呼吸氧化酶，由三个氮调节启动子表达，NtcA 结合在这些启动子上。在这三个位点，NtcA 结合被 PipX 增强。因此，PipX 对影响 NtcA 活性的基因表达有直接影响。
