The Maize Imprinted Gene Floury3 Encodes a PLATZ Protein Required for tRNA and 5S rRNA Transcription through Interaction with RNA Polymerase III
The Maize Imprinted Gene Floury3 Encodes a PLATZ Protein Required for tRNA and 5S rRNA Transcription through Interaction with RNA Polymerase III
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玉米印记基因 Flory3 通过与 RNA 聚合酶 III 相互作用编码 tRNA 和 5S rRNA 转录所需的 PLATZ 蛋白
DOI：
10.1105/tpc.17.00576
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发表时间：
2017-10-01
期刊：
影响因子：
11.6
通讯作者：
Wu, Yongrui
中科院分区：
文献类型：
--
作者：
Li, Qi;Wang, Jiechen;Wu, Yongrui
玉米（Zea mays） fl3是一种典型的半显性负突变体，在胚乳中表现出严重缺陷，而fl3植株在其他方面表现正常。我们克隆了fl3基因并确定其编码PLATZ（植物AT-rich sequence and zinc binding）蛋白。fl3的突变导致保守的PLATZ结构域的Asn-to-His替换，产生显性等位基因。FI3在淀粉胚乳细胞中特异性表达，并受基因组印记的调控，这可能导致fl3在通过雄性传播时表达受到抑制，这可能是半显性行为的结果。酵母双杂交筛选和双分子荧光素酶互补实验表明，FL3与RNA聚合酶III （RNAPIII）转录复合体的两个关键因子RNA聚合酶III亚基53 （RPC53）和转录因子c1 （TFC1）相互作用。在fl3胚乳中，RNAPIII转录的许多trna和5S rRNA水平显著降低，提示错误折叠的f13蛋白可能会损害RNAPIII的功能。fl3突变体的转录组发生显著改变，其中下调基因主要富集于与翻译、核糖体、错误折叠蛋白反应和营养库活性相关的途径中。综上所述，这些变化可能导致fl3种子胚乳发育和储存储备填充缺陷。
Maize (Zea mays) floury3 (fl3) is a classic semidominant negative mutant that exhibits severe defects in the endosperm but fl3 plants otherwise appear normal. We cloned the fl3 gene and determined that it encodes a PLATZ (plant AT-rich sequence and zinc binding) protein. The mutation in fl3 resulted in an Asn-to-His replacement in the conserved PLATZ domain, creating a dominant allele. FI3 is specifically expressed in starchy endosperm cells and regulated by genomic imprinting, which leads to the suppressed expression of fl3 when transmitted through the male, perhaps as a consequence the semidominant behavior. Yeast two-hybrid screening and bimolecular luciferase complementation experiments revealed that FL3 interacts with the RNA polymerase III subunit 53 (RPC53) and transcription factor class C 1 (TFC1), two critical factors of the RNA polymerase III (RNAPIII) transcription complex. In the fl3 endosperm, the levels of many tRNAs and 5S rRNA that are transcribed by RNAPIII are significantly reduced, suggesting that the incorrectly folded f 13 protein may impair the function of RNAPIII. The transcriptome is dramatically altered in fl3 mutants, in which the downregulated genes are primarily enriched in pathways related to translation, ribosome, misfolded protein responses, and nutrient reservoir activity. Collectively, these changes may lead to defects in endosperm development and storage reserve filling in fl3 seeds.