SpoIIE governs the phosphorylation state of a protein regulating transcription factor oM during sporulation in Bacillus subtilis-猫眼课题宝

SpoIIE 在枯草芽孢杆菌孢子形成过程中控制转录因子 oM 蛋白的磷酸化状态

DOI：

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发表时间：

2005

期刊：

影响因子：

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通讯作者：

中科院分区：

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文献类型：

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作者：

Fabrizio;Arigoni;Leonard;DUNCANt;Scott ALPERt;Richard LOSICKt;P. Stragier

枯草芽孢杆菌孢子形成过程中转录因子Mo的细胞特异性激活受涉及蛋白SpoIIE、Spo-IIAA和SpoIIAB的调节途径控制。SpoIIAB是或的拮抗剂，SpoIIAA是SpoIIAB的拮抗剂，其能够克服SpoIIAB介导的对oe的抑制。反过来，SpoIIAA由SpoIIAB负调控，SpoIIAB使丝氨酸58上的SpoIIAA磷酸化。SpoIIAA也受SpoIIE的正调控，SpoIIE使SpoIIAA的磷酸化形式SpoIIAA-P去磷酸化。在这里，使用等电聚焦和蛋白质印迹分析来检测SpoIIAA在体内的磷酸化状态。发现SpoIIAA在野生型细胞中孢子形成期间主要处于磷酸化状态，但也可以检测到未磷酸化的蛋白质的显著部分。与SpoIIE控制SpoIIAA-P去磷酸化的观点一致，SpoIIAA在spoIIE突变细胞中完全处于磷酸化状态。相反，spoIIIE的过表达导致未磷酸化的SpoIIAA与SpoIIAA-P的比率增加，并导致分裂前孢子囊中eo的不适当激活。

Cell-specific activation of the transcription factor Mo during sporulation in Bacillus subtilis is controlled by a regulatory pathway involving the proteins SpoIIE, Spo- IIAA, and SpoIIAB. SpoIIAB is an antagonist of or, and SpoIIAA, which is capable of overcoming SpoIIAB-mediated inhibition of oe, is an antagonist of SpoIIAB. SpoIIAA is, in turn, negatively regulated by SpoIIAB, which phosphorylates SpoIIAA on serine 58. SpoIIAA is also positively regulated by SpoIIE, which dephosphorylates SpoIIAA-P, the phosphory- lated form of SpoIIAA. Here, isoelectric focusing and Western blot analysis were used to examine the phosphorylation state of SpoIIAA in vivo. SpoIIAA was found to be largely in the phosphorylated state during sporulation in wild-type cells but a significant portion of the protein that was unphosphorylated could also be detected. Consistent with the idea that SpoIIE governs dephosphorylation of SpoIIAA-P, SpoIIAA was en-tirely in the phosphorylated state in spoIIE mutant cells. Conversely, overexpression of spoIllE led to an increase in the ratio of unphosphorylated SpoIIAA to SpoIIAA-P and caused inappropriate activation of eo in the predivisional sporangium.