Characterization of LRP, a leucine-rich repeat (LRR) protein from tomato plants that is processed during pathogenesis
Characterization of LRP, a leucine-rich repeat (LRR) protein from tomato plants that is processed during pathogenesis
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DOI：
10.1046/j.1365-313x.1996.10020315.x
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发表时间：
1996-08-01
期刊：
影响因子：
7.2
通讯作者：
Vera, P
中科院分区：
文献类型：
--
作者：
Tornero, P;Mayda, E;Vera, P
本文介绍了番茄植物新基因 LRP 的分离和表征。推导的氨基酸序列表明编码的蛋白质富含亮氨酸，并且包含有趣的结构基序。 LRP 包含典型的 24 个氨基酸富含亮氨酸重复 (LRR) 序列的四个串联重复序列，存在于介导分子识别和/或相互作用过程的不同蛋白质中。 LRP 的基因组组织和内含子-外显子排列支持 LRP 中存在的 LRR 结构域通过外显子复制和改组进化的假设。 LRP 表达分析和编码蛋白的免疫组织化学定位研究表明，该基因处于发育调控下，表现出组织特异性，特别是在中柱的某些细胞类型中，如韧皮部纤维、原木质部的薄壁细胞，以及构成次生木质部射线的细胞文件中。结果表明，该基因在感染柑橘外皮质类病毒的患病番茄植株中上调。然而，在这种致病背景下，LRP 被宿主诱导的细胞外蛋白酶蛋白水解为较低分子量的形式。 LRP 的结构特征、其表达的时空模式及其在发病过程中的翻译后加工表明，该蛋白作为候选分子，可以介导正常和/或发病相关条件下植物细胞外基质中发生的识别和相互作用事件。
This paper describes the isolation and characterization of LRP, a new gene from tomato plants. The deduced amino acid sequence showed that the encoded protein is enriched in leucine, and contains interesting structural motifs. LRP contains four tandem repeats of a canonical 24 amino acid leucine-rich repeat (LRR) sequence present in different proteins that mediates molecular recognition and/or interaction processes. Genomic organization and intron-exon arrangement of LRP favor the hypothesis that the LRR domains present in LRP evolved by exon duplication and shuffling. LRP expression analysis and immunohistochemical localization studies of the encoded protein indicate that the gene is under developmental regulation exhibiting tissue-specificity, particularly in certain cell types of the stele, like phloem fibers, parenchyma cells of the protoxylem, and in the cell files that constitute the rays of the secondary xylem. It is shown that this gene is upregulated in diseased tomato plants infected with citrus exocortis viroid. However, in this pathogenic context, LRP is processed proteolytically to a lower molecular weight form by a host-induced extracellular protease. The structural characteristics of LRP, its spatio-temporal pattern of expression, and its post-translational processing during pathogenesis, suggest this protein as a candidate molecule that may mediate recognition and interaction events taking place in the plant extracellular matrix under normal and/or pathogenesis-related conditions.