NAI1 gene encodes a basic-helix-loop-helix-type putative transcription factor that regulates the formation of an endoplasmic reticulum-derived structure, the ER body
NAI1 gene encodes a basic-helix-loop-helix-type putative transcription factor that regulates the formation of an endoplasmic reticulum-derived structure, the ER body
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DOI：
10.1105/tpc.021154
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发表时间：
2004-06-01
期刊：
影响因子：
11.6
通讯作者：
Hara-Nishimura, I
中科院分区：
文献类型：
--
作者：
Matsushima, R;Fukao, Y;Hara-Nishimura, I
植物细胞发育各种类型的内质网（ER）衍生结构，具有特定的功能。内质网小体是拟南芥内质网衍生的隔室，呈纺锤状结构。NAI1基因调控内质网小体的发育，因为NAI1的突变会破坏内质网小体的形成。为了更好地了解NAI1的作用，我们使用定位克隆策略克隆了NAI1基因。NAI1 -1突变体在At2g22770 （NAI1基因）的一个内含子受体位点上发生了单核苷酸变化。由于这种突变，在NAI1 -1突变体中发生了NAI1 mRNA的异常剪接。NAI1编码一个具有碱性螺旋-环-螺旋结构域的转录因子。NAI1突变体中NAI1诱导ER小体的瞬时表达。双向电泳和RT-PCR分析显示，在甲突变体中，一种推测的凝集素在mRNA和蛋白质水平上都受到抑制，β -葡萄糖苷酶（PYK10）也是如此。我们的研究结果提供了bHLH蛋白在ER小体形成中起作用的直接证据。
Plant cells develop various types of endoplasmic reticulum (ER)-derived structures with specific functions. ER body, an ER-derived compartment in Arabidopsis thaliana, is a spindle-shaped structure. The NAI1 gene regulates the development of ER bodies because mutation of NAI1 abolishes the formation of ER bodies. To better understand the role of NAI1, we cloned the NAI1 gene using a positional cloning strategy. The nai1-1 mutant had a single nucleotide change at an intron acceptor site of At2g22770 (NAI1 gene). Because of this mutation, aberrant splicing of NAI1 mRNA occurs in the nai1-1 mutant. NAI1 encodes a transcription factor that has a basic-helix-loop-helix (bHLH) domain. Transient expression of NAI1 induced ER bodies in the nai1-1 mutant. Two-dimensional electrophoresis and RT-PCR analyses showed that a putative lectin was depressed at both the mRNA and protein levels in nail mutants, as was a beta-glucosidase (PYK10). Our results provide direct evidence that a bHLH protein plays a role in the formation of ER bodies.