Ethylene-regulated expression of a tomato fruit ripening gene encoding a proteinase inhibitor I with a glutamic residue at the reactive site.
Ethylene-regulated expression of a tomato fruit ripening gene encoding a proteinase inhibitor I with a glutamic residue at the reactive site.
复制标题
乙烯调节番茄果实成熟基因的表达，该基因编码在反应位点具有谷氨酸残基的蛋白酶抑制剂 I。
DOI：
10.1073/pnas.85.21.8012
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发表时间：
1988
影响因子：
11.1
通讯作者：
Fischer,RL
中科院分区：
文献类型：
--
作者：
Margossian,LJ;Federman,AD;Giovannoni,JJ;Fischer,RL
我们报告分离番茄（番茄）的乙烯反应的蛋白酶抑制剂基因家族的成员。全长cDNA克隆的DNA序列分析表明，乙烯响应基因是远相关的番茄蛋白酶抑制剂I基因，具有53%的序列同一性。预测的氨基酸序列揭示47%和45%的序列同一性与番茄和马铃薯蛋白酶抑制剂I多肽，分别。此外，乙烯响应性抑制剂已经进化出与抑制剂I家族的其他成员完全不同的基因表达模式和抑制特异性。凝胶印迹杂交实验表明，与番茄蛋白酶抑制剂I基因不同，它不会在受伤的叶片中诱导。相反，它是由植物激素乙烯在叶片和果实成熟过程中激活。此外，乙烯响应性抑制剂表现出一种新的反应位点，具有谷氨酸作为P1残基。这表明乙烯响应性蛋白酶抑制剂不与胰凝乳蛋白酶反应，如蛋白酶抑制剂I，但它与在谷氨酸残基处裂解的蛋白水解酶反应，如金黄色葡萄球菌V8蛋白酶，其没有抑制剂是已知的。最后，基因组克隆的分离和分析表明，乙烯反应蛋白酶抑制剂基因与另一个尚未鉴定的协同表达基因紧密相连。我们讨论了这些结果方面的功能和番茄蛋白酶抑制剂基因的进化。
We report the isolation from tomato (Lycopersicon esculentum) of an ethylene-responsive member of the proteinase inhibitor gene family. DNA sequence analysis of a full-length cDNA clone indicates that the ethylene-responsive gene is distantly related to the tomato proteinase inhibitor I gene, having 53% sequence identity. The predicted amino acid sequence reveals 47% and 45% sequence identity with the tomato and potato proteinase inhibitor I polypeptides, respectively. Additionally, the ethylene-responsive inhibitor has evolved a completely different pattern of gene expression and inhibitory specificity than other members of the inhibitor I family. Gel blot hybridization experiments show that, unlike the tomato proteinase inhibitor I gene, it is not induced in wounded leaves. In contrast, it is activated by the plant hormone ethylene in leaves and during fruit ripening. Furthermore, the ethylene-responsive inhibitor exhibits a novel reactive site, having glutamic acid as the P1 residue. This suggests that the ethylene-responsive proteinase inhibitor does not react with chymotrypsin, as does proteinase inhibitor I, but that it reacts with proteolytic enzymes that cleave at glutamic residues, such as the Staphylococcus aureus V8 proteinase, for which no inhibitors are known. Finally, isolation and analysis of a genomic clone reveals that the ethylene-responsive proteinase inhibitor gene is tightly linked to another, yet unidentified, coordinately expressed gene. We discuss these results with regard to the function and evolution of proteinase inhibitor genes in tomato.