THE HOMEOBOX GENE ATK1 OF ARABIDOPSIS-THALIANA IS EXPRESSED IN THE SHOOT APEX OF THE SEEDLING AND IN FLOWERS AND INFLORESCENCE STEMS OF MATURE PLANTS
THE HOMEOBOX GENE ATK1 OF ARABIDOPSIS-THALIANA IS EXPRESSED IN THE SHOOT APEX OF THE SEEDLING AND IN FLOWERS AND INFLORESCENCE STEMS OF MATURE PLANTS
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DOI：
10.1007/bf00021196
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发表时间：
1995-07-01
影响因子：
5.1
通讯作者：
SMEEKENS, S
中科院分区：
文献类型：
--
作者：
DOCKX, J;QUAEDVLIEG, N;SMEEKENS, S
同源结构域是一个存在于真核生物调节蛋白大家族中的dna结合结构域。同源结构域蛋白已被证明在控制各种生物体的发育程序中起关键作用。在这里，我们报道了从拟南芥中分离并鉴定了一个名为ATK1的同源盒基因。该基因以玉米KN1基因的同源盒结构域为探针进行分离。ATK1的同源结构域与玉米KN1基因的同源结构域高度同源（81%），但同源结构域外的同源性较差。因此，ATK1可能不是来自玉米的KNI基因的拟南芥同源物。它包含四个不变氨基酸残基，存在于所有其他同源结构域蛋白的识别螺旋3中。在同源域外发现了一个富含天冬氨酸和谷氨酸残基的区域，这表明ATK1是一个转录激活因子。该基因含有4个内含子，与玉米的KN1基因和水稻的Osh1基因相似。引物延伸显示存在两个转录起始位点。真实转录物的先导序列长342个核苷酸，包含两个上游开放阅读框。ATK1在幼苗的茎尖强烈表达，而在成熟植物中，该基因主要在花和花序茎中表达。这种表达模式让人想起玉米的KN1基因，因此ATK1可能类似地参与决定细胞命运。
The homeodomain is a DNA-binding domain present in a large family of eukaryotic regulatory proteins. Homeodomain proteins have been shown to play key roles in controlling developmental programs in various organisms. Here we report the isolation and characterisation of a homeobox gene from Arabidopsis thaliana designated ATK1. The gene was isolated using as a probe the homeobox domain of the KN1 gene from maize. The homeodomain of ATK1 is highly homologous to the homeodomain of the KN1 gene of maize (81%) but shows only poor homology outside the homeodomain. Therefore ATK1 is probably not the Arabidopsis homologue of the KNI gene from maize. It contains the four invariant amino acid residues present in the recognition helix 3 of all other homeodomain proteins. Outside the homeodomain a region rich in aspartate and glutamate residues is found suggesting that ATK1 is a transcriptional activator. The gene contains four introns which is similar in the KN1 gene of maize and the Osh1 gene of rice. Primer extension reveals the presence of two transcription initiation sites. The leader sequence of the genuine transcript is 342 nucleotides long and contains two upstream open reading frames. ATK1 is strongly expressed in the shoot apex of seedlings, while in mature plants the gene is primarily expressed in flowers and inflorescence stems. Such an expression pattern is reminiscent of that of the KN1 gene of maize and therefore ATK1 could similarly be involved in determining cell fate.