DSP1 and DSP4 act synergistically in snRNA 3' end maturation and pollen growth
DSP1 and DSP4 act synergistically in snRNA 3' end maturation and pollen growth
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DOI：
10.1104/pp.19.00231
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发表时间：
2019
期刊：
影响因子：
7.4
通讯作者：
Yunfeng Liu
中科院分区：
文献类型：
--
作者：
Xuepiao Pu;Chunmei Meng;Weili Wang;Siyu Yang;Yuan Chen;Qingjun Xie;Bin Yu;Yunfeng Liu
小核RNA（snRNA）在剪接体组装和剪接中起着重要作用。大多数snRNA由DNA依赖性RNA聚合酶II（Pol II）转录，并需要3′端核酸内切酶切割。我们之前已经证明，拟南芥（Arabidopsis thaliana）缺陷snRNA加工1（DSP 1）复合体，由至少5个亚基组成，负责snRNA 3′成熟，是植物发育所必需的。然而，DSP 1复合物亚基如何共同作用以加工snRNA仍不清楚。在这里，我们表明，DSP 4，金属β-内酰胺酶家族的成员，通过其β-Casp结构域与DSP 1物理相互作用。nulldsp 4 - 1突变体具有多效性的发育缺陷，包括花粉发育受损、pre-snRNA转录减少和3′端成熟减少，与dsp 1 - 1突变体的表型相似。有趣的是，dsp 1 -1和dsp 4 - 1双突变体表现出完全的雄性不育性，前snRNA转录和3′端成熟减少，这与sp1 - 1和sp 4 -1不同。此外，在snRNA位点上的Pol II占有率indsp 1 -1 dsp 4 - 1比任一单个突变体低。我们还检测到了错误切割的前snRNA indsp 1 -1 dsp 4 -1，但没有indsp 1 - 1 ordsp 4 -1。总而言之，这些数据表明DSP 1和DSP 4的功能对于花粉发育至关重要，并且两者协同促进前snRNA转录和3 '端加工效率和准确性。
Small nuclear RNAs (snRNAs) play essential roles in spliceosome assembly and splicing. Most snRNAs are transcribed by the DNA-dependent RNA polymerase II (Pol II) and require 3′-end endonucleolytic cleavage. We have previously shown that the Arabidopsis (Arabidopsis thaliana) Defective in snRNA Processing 1 (DSP1) complex, composed of at least five subunits, is responsible for snRNA 3′ maturation and is essential for plant development. Yet it remains unclear how DSP1 complex subunits act together to process snRNAs. Here, we show that DSP4, a member of the metallo-β-lactamase family, physically interacts with DSP1 through its β-Casp domain. Nulldsp4-1mutants have pleiotropic developmental defects, including impaired pollen development and reduced pre-snRNA transcription and 3′ maturation, resembling the phenotype of thedsp1-1mutant. Interestingly,dsp1-1 dsp4-1double mutants exhibit complete male sterility and reduced pre-snRNA transcription and 3′-end maturation, unlikedsp1-1ordsp4-1. In addition, Pol II occupancy at snRNA loci is lower indsp1-1 dsp4-1than in either single mutant. We also detected miscleaved pre-snRNAs indsp1-1 dsp4-1,but not indsp1-1ordsp4-1. Taken together, these data reveal that DSP1 and DSP4 function is essential for pollen development, and that the two cooperatively promote pre-snRNA transcription and 3′-end processing efficiency and accuracy.