Identification of a Short Highly Conserved Amino Acid Sequence as the Functional Region Required for Posttranscriptional Autoregulation of the Cystathionine γ-Synthase Gene in Arabidopsis *
Identification of a Short Highly Conserved Amino Acid Sequence as the Functional Region Required for Posttranscriptional Autoregulation of the Cystathionine γ-Synthase Gene in Arabidopsis *
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DOI：
10.1074/jbc.m204645200
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发表时间：
2002-09
期刊：
影响因子：
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通讯作者：
Kimihiro Ominato;H. Akita;A. Suzuki;F. Kijima;T. Yoshino;M. Yoshino;Y. Chiba;H. Onouchi;S. Naito
中科院分区：
文献类型：
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作者：
Kimihiro Ominato;H. Akita;A. Suzuki;F. Kijima;T. Yoshino;M. Yoshino;Y. Chiba;H. Onouchi;S. Naito
胱硫醚γ-合酶（CGS）是催化植物体内Met生物合成的第一个关键步骤。我们先前已经表明，CGS基因的表达在mRNA稳定性水平上受到反馈调节，并且由CGS基因本身的第一外显子编码的氨基酸序列负责该调节（千叶，Y.，石川，M.，Kijima，F.，泰森河H、金，J.，Yamamoto，A.，Nambara，E.，Leustek，T.，瓦尔斯格罗夫河M.，和Naito，S.（1999）Science 286，1371-1374）。为了鉴定CGS外显子1内的功能区域，进行缺失分析。结果表明，外显子1的41个氨基酸的区域在植物中高度保守，这是必要的和充分的调控。分析体内和体外产生的突变，取消了监管确定的功能重要的氨基酸为11-13个残基在这个保守的区域。通过保守区域内的缺失分析证实了这些残基的重要性。这些研究确定了CGS基因转录后自动调节所需的CGS外显子1的功能区域为（A）RRNCSNIGVAQ（I），第一个和最后一个残基不确定。该序列在高等植物的CGS序列中几乎是完全保守的，但在公共数据库的其他地方找不到。
Cystathionine γ-synthase (CGS) catalyzes the first committed step of Met biosynthesis in plants. We have previously shown that expression of the gene for CGS is feedback-regulated at the level of mRNA stability, and that the amino acid sequence encoded by the first exon of the CGS gene itself is responsible for the regulation (Chiba, Y., Ishikawa, M., Kijima, F., Tyson, R. H., Kim, J., Yamamoto, A., Nambara, E., Leustek, T., Wallsgrove, R. M., and Naito, S. (1999) Science 286, 1371–1374). To identify the functional region within CGS exon 1, deletion analysis was performed. The results showed that the 41-amino acid region of exon 1 highly conserved among plants is necessary and sufficient for the regulation. Analyses of in vivo and in vitrogenerated mutations that abolish the regulation identified the functionally important amino acids as 11–13 residues within this conserved region. The importance of these residues was confirmed by deletion analysis within the conserved region. These studies identified the functional region of CGS exon 1 required for the posttranscriptional autoregulation of the CGS gene as (A)RRNCSNIGVAQ(I), with uncertainty of the first and last residues. This sequence is almost perfectly conserved among CGS sequences of higher plants but cannot be found elsewhere in the public databases.