HIGH CHLOROPHYLL FLUORESCENCE145 Binds to and Stabilizes the psaA 5′ UTR via a Newly Defined Repeat Motif in Embryophyta
HIGH CHLOROPHYLL FLUORESCENCE145 Binds to and Stabilizes the psaA 5′ UTR via a Newly Defined Repeat Motif in Embryophyta
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DOI：
10.1105/tpc.15.00234
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发表时间：
2015-09-01
期刊：
影响因子：
11.6
通讯作者：
Meurer, Joerg
中科院分区：
文献类型：
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作者：
Manavski, Nikolay;Torabi, Salar;Meurer, Joerg
幼苗致死的拟南芥高叶绿素荧光145(Hcf145)突变导致了叶绿体三顺反子psaA-psaB-rps 14mRNA的稳定性降低和光系统I(PSI)缺陷。在这里，我们对HCF145基因进行了遗传定位，该基因编码了一个植物特有的、叶绿体定位的模块化蛋白，其中包含两个与聚酮环化酶家族相关的同源结构域，其中包括37个功能未知的注释拟南芥蛋白。在C末端另外两个高度保守且以前未被鉴定的串联重复基序，在这里被称为转录结合基序重复(TMR)结构域，赋予HCF145序列特异性的RNA结合能力。同源TMR基序经常在绿藻和红藻的不同蛋白中以多个重复的形式存在，在功能未知的蓝藻Microcoleus spPCC7113中也存在。HCF145是维管束植物中发现的唯一TMR蛋白。对拟南芥和条锈菌中hcf145突变体的详细分析以及体内和体外的RNA结合分析表明，hcf145已被招募到胚芽植物中，通过与其59个非翻译区的特异性结合来稳定psaA-psaB-rps 14mRNA。聚酮环化酶相关基序支持TMR与psaA RNA的结合，推测在根据植物细胞的需要调节PSI水平方面具有调节作用。
The seedling-lethal Arabidopsis thaliana high chlorophyll fluorescence145 (hcf145) mutation leads to reduced stability of the plastid tricistronic psaA-psaB-rps14 mRNA and photosystem I (PSI) deficiency. Here, we genetically mapped the HCF145 gene, which encodes a plant-specific, chloroplast-localized, modular protein containing two homologous domains related to the polyketide cyclase family comprising 37 annotated Arabidopsis proteins of unknown function. Two further highly conserved and previously uncharacterized tandem repeat motifs at the C terminus, herein designated the transcript binding motif repeat (TMR) domains, confer sequence-specific RNA binding capability to HCF145. Homologous TMR motifs are often found as multiple repeats in quite diverse proteins of green and red algae and in the cyanobacterium Microcoleus sp PCC 7113 with unknown function. HCF145 represents the only TMR protein found in vascular plants. Detailed analysis of hcf145 mutants in Arabidopsis and Physcomitrella patens as well as in vivo and in vitro RNA binding assays indicate that HCF145 has been recruited in embryophyta for the stabilization of the psaA-psaB-rps14 mRNA via specific binding to its 59 untranslated region. The polyketide cyclase-related motifs support association of the TMRs to the psaA RNA, presumably pointing to a regulatory role in adjusting PSI levels according to the requirements of the plant cell.