Molecular mechanism of regulation of methionine biosynthesis by mRNA stability : Studies using mto1 mutants of Arabidopsis.

通过 mRNA 稳定性调节蛋氨酸生物合成的分子机制：使用拟南芥 mto1 突变体进行的研究。

• 批准号: 11440230
• 负责人: NAITO Satoshi
• 金额: $ 10.69万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11440230/
• 关键词: methionine biosynthesis; Arabidopsis thaliana; mutant; mRNA stability

Cystathionine gamma-synthase (CGS) of Arabidopsis has 563 amino acids and the first exon codes for 183 amino acids. Comparison of CGS sequence among higher plants reveals a 35 amino acid region ("MTO1 region") within the exon 1 that is highly conserved among plant species. This suggests that this region has a role in the regulation of CGS gene expression.Sequential deletion mutants within the CGS exon 1 was constructed from both the N-and C-termini. The deletion constructs were fused in-frame with a reporter gene, beta-glucuronidase (GUS), and placed under the control of cauliflower mosaic virus (CaMV) 35S RNA promoter and their response to Met application was analyzed by transient expression experiments. The results of GUS assay indicated that the constructs carrying the MTO1 region respond to Met application while those do not carry the MTO1 region do not. In addition, when mto1-1 mutation was introduced to those constructs that carry the MTO1 region, the response disappeared.Deletions in both sides of MTO1 were also constructed and tested for their response to Met application. The results suggest that the MTO1 region is sufficient for the downregulation in response to Met application.

拟南芥CGS基因由563个氨基酸组成，第一外显子编码183个氨基酸。比较高等植物的CGS序列，发现在外显子1中有一个35个氨基酸的区域(MTO1区)，这在植物中是高度保守的。这表明该区域在CGS基因的表达调控中起作用。CGS外显子1的序列缺失突变体是从N-末端和C-末端构建的。将缺失构建体与报告基因β-葡萄糖醛酸苷酶(GUS)框内融合，置于花椰菜花叶病毒(CaMV)35S RNA启动子的控制下，通过瞬时表达实验分析它们对Met处理的响应。GUS分析结果表明，携带MTO1区的构建体对Met应用有反应，而不携带MTO1区的构建体不响应Met的应用。此外，当mto1-1突变被引入到那些携带MTO1区域的构建物中时，这种反应消失。也构建了MTO1两侧的缺失，并测试了它们对Met应用的响应。结果表明，MTO1区足以响应Met的作用而下调。

项目成果

Derek Bartlem: "Mutation in the threonine synthase gene results in an over-accumulation of soluble methionine in Arabidopsis."Plant Physiology. 123・5. 101-110 (2000)

Derek Bartlem：“苏氨酸合酶基因的突变导致拟南芥中可溶性蛋氨酸的过度积累。”植物生理学 123・5 (2000)。

Yukako Chiba: "Evidence for autoregulation of cystathionine g-synthase mRNA stability in Arabidopsis"Science. 286-5443. 1371-1374 (1999)

Yukako Chiba：“拟南芥中胱硫醚 g-合酶 mRNA 稳定性自动调节的证据”《科学》。

Yukako Chiba: "Evidence for autoregulation of cystathionine γ-synthase mRNA stability in Arabidopsis."Science. 286・5443. 1371-1374 (1999)

Yukako Chiba：“拟南芥中胱硫醚 γ-合酶 mRNA 稳定性的自动调节证据。”《科学》286·5443（1999）。

Derek Bartlem: "Mutation in the threonine synthase gene results in an overaccumulation of soluble methionine in Arabidopsis."Plant Physiology. 123(5). 101-110 (2000)

德里克·巴特勒姆：“苏氨酸合酶基因突变导致拟南芥中可溶性蛋氨酸过度积累。”植物生理学。

Derek Bartlem: "Genomic nucleotide sequence of the Arabidopsis threonine synthase gene (Accession No.AB027151)."Plant Physiology. 120 (4). 1205-1205 (1999)

Derek Bartlem：“拟南芥苏氨酸合酶基因的基因组核苷酸序列（登录号AB027151）。”植物生理学。