Pollen-Expressed Transcription Factor 2 Encodes a Novel Plant-Specific TFIIB-Related Protein that Is Required for Pollen Germination and Embryogenesis in Arabidopsis
Pollen-Expressed Transcription Factor 2 Encodes a Novel Plant-Specific TFIIB-Related Protein that Is Required for Pollen Germination and Embryogenesis in Arabidopsis
复制标题
花粉表达转录因子 2 编码一种新型植物特异性 TFIIB 相关蛋白，该蛋白是拟南芥花粉萌发和胚胎发生所需的
DOI：
10.1093/mp/sst083
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发表时间：
2013-07-01
期刊：
影响因子：
27.5
通讯作者：
Ye, De
中科院分区：
文献类型：
--
作者：
Niu, Qian-Kun;Liang, Yan;Ye, De
PTF 2是一种新的植物特异性转录因子，在体外能与TATA盒结合蛋白2（TBP2）相互作用并与双链DNA（dsDNA）结合。它在拟南芥花粉萌发和胚胎发生过程中起着重要作用，花粉萌发和胚胎发生在植物有性生殖过程中起着重要作用。这些过程需要大量的基因表达。真核生物核基因的转录是由三个保守的RNA聚合酶与一组辅助性通用转录因子（GTF）（包括B型GTF）共同作用完成的。B型GTF在植物繁殖中的作用仍然知之甚少。在这里，我们报告一个新的植物特异性TFIIB相关基因PTF2在拟南芥中的功能特性。PTF2突变导致花粉萌发失败。花粉拯救实验表明，该突变也破坏了胚胎发生，导致种子败育。PTF2在发育中的花粉和其他细胞分裂和分化活跃的组织中大量表达，包括胚和茎尖分生组织。PTF2蛋白与拟南芥中其他已知的TFIIB和TFIIB相关蛋白具有较低的氨基酸序列相似性。它可以与TATA盒结合蛋白2（TBP2）相互作用，并与其他已知的TFIIB和TFIIB相关蛋白一样结合双链DNA（dsDNA）。此外，PTF 2可以形成同源二聚体，并与RNA聚合酶（RNAP）的亚基相互作用，这意味着它可能参与RNAP的转录。这些结果表明，PTF2在拟南芥花粉萌发和胚胎发生中起着至关重要的作用，可能是通过与TBP2和RNAP亚基的相互作用来调节基因表达。
PTF2 is a novel plant-specific TFIIB-related transcription factor that can interact with TATA-box binding protein 2 (TBP2) and bind to the double-stranded DNA (dsDNA) in vitro. It plays important roles in pollen germination and embryogenesis in Arabidopsis.Pollen germination and embryogenesis are important to sexual plant reproduction. The processes require a large number of genes to be expressed. Transcription of eukaryotic nuclear genes is accomplished by three conserved RNA polymerases acting in association with a set of auxiliary general transcription factors (GTFs), including B-type GTFs. The roles of B-type GTFs in plant reproduction remain poorly understood. Here we report functional characterization of a novel plant-specific TFIIB-related gene PTF2 in Arabidopsis. Mutation in PTF2 caused failure of pollen germination. Pollen-rescue revealed that the mutation also disrupted embryogenesis and resulted in seed abortion. PTF2 is expressed prolifically in developing pollen and the other tissues with active cell division and differentiation, including embryo and shoot apical meristem. The PTF2 protein shares a lower amino acid sequence similarity with other known TFIIB and TFIIB-related proteins in Arabidopsis. It can interact with TATA-box binding protein 2 (TBP2) and bind to the double-stranded DNA (dsDNA) as the other known TFIIB and TFIIB-related proteins do. In addition, PTF2 can form a homodimer and interact with the subunits of RNA polymerases (RNAPs), implying that it may be involved in the RNAPs transcription. These results suggest that PTF2 plays crucial roles in pollen germination and embryogenesis in Arabidopsis, possibly by regulating gene expression through interaction with TBP2 and the subunits of RNAPs.