MicroRNA control of PHABULOSA in leaf development:: importance of pairing to the microRNA 5′ region
MicroRNA control of PHABULOSA in leaf development:: importance of pairing to the microRNA 5′ region
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DOI：
10.1038/sj.emboj.7600340
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发表时间：
2004-08-18
期刊：
影响因子：
11.4
通讯作者：
Bartel, DP
中科院分区：
文献类型：
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作者：
Mallory, AC;Reinhart, BJ;Bartel, DP
MicroRNAs （miRNAs）类似于22核苷酸的非编码rna，可以通过指导mRNA降解或抑制有效翻译来调节基因表达。PHABULOSA （PHB）和PHAVOLUTA （PHV）的显性突变映射到miR165/166互补位点，并在体外损害mirna引导的这些mrna的切割。在这里，我们证实了导致PHB -d突变体发育缺陷的是miRNA配对中断，而不是PHB蛋白序列的改变。在植物中，破坏miRNA互补位点中心附近的miRNA配对比远端错配的发育后果要轻得多。这些差异与体外miRNA定向切割效率的差异相关，其中错配扫描显示，与miRNA 5‘区错配相比，miRNA中心和3’端对错配的耐受性更高。在这方面，miR165/166在配对要求上与动物mirna相似。无论转录后抑制的模式如何，也无论它是否发生在植物或动物中，与小沉默RNA的5'部分配对似乎都至关重要，这支持了沉默RNA的这一区域与目标配对成核的模型。
MicroRNAs (miRNAs) are similar to22-nucleotide noncoding RNAs that can regulate gene expression by directing mRNA degradation or inhibiting productive translation. Dominant mutations in PHABULOSA (PHB) and PHAVOLUTA (PHV) map to a miR165/166 complementary site and impair miRNA-guided cleavage of these mRNAs in vitro. Here, we confirm that disrupted miRNA pairing, not changes in PHB protein sequence, causes the developmental defects in phb-d mutants. In planta, disrupting miRNA pairing near the center of the miRNA complementary site had far milder developmental consequences than more distal mismatches. These differences correlated with differences in miRNA-directed cleavage efficiency in vitro, where mismatch scanning revealed more tolerance for mismatches at the center and 3' end of the miRNA compared to mismatches to the miRNA 5' region. In this respect, miR165/166 resembles animal miRNAs in its pairing requirements. Pairing to the 5' portion of the small silencing RNA appears crucial regardless of the mode of post-transcriptional repression or whether it occurs in plants or animals, supporting a model in which this region of the silencing RNA nucleates pairing to its target.