RAD5a ubiquitin ligase is involved in ubiquitination of Arabidopsis thaliana proliferating cell nuclear antigen
RAD5a ubiquitin ligase is involved in ubiquitination of Arabidopsis thaliana proliferating cell nuclear antigen
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DOI：
10.1093/jxb/ers368
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发表时间：
2013-02-01
影响因子：
6.9
通讯作者：
Tanaka, Katsunori
中科院分区：
文献类型：
--
作者：
Strzalka, Wojciech;Bartnicki, Filip;Tanaka, Katsunori
增殖细胞核抗原（PCNA）在酵母和哺乳动物细胞中被泛素后修饰。广泛认为，在酵母中，单泛素化和多泛素化的PCNA参与DNA复制后修复的不同途径。本研究表明，植物泛素和PCNA之间的相互作用在植物细胞。利用不同的方法，已经证明拟南芥RAD5a泛素连接酶参与植物PCNA的翻译后修饰。选择拟南芥泛素缀合酶（AtUBC）的特性的详细分析表明，酵母RAD 6（AtUBC 2）的植物同源物是足够的泛素连接酶的情况下，单泛素AtPCNA。使用所选AtUBC蛋白与AtRAD 5a的不同组合，证明植物具有使用不同途径来泛素化PCNA的潜力。拟南芥PCNA 1和PCNA 2的分析没有显示出这两种蛋白质之间的泛素化模式的实质性差异。在真核生物中保守的拟南芥PCNA的主要泛素化靶标是赖氨酸164。两者合计，所呈现的结果清楚地证明了拟南芥UBC和RAD 5a蛋白参与植物PCNA在赖氨酸164处的泛素化。这些数据显示了植物遍在蛋白化系统的复杂性，并提出了有关其在植物细胞中调节的新问题。
The proliferating cell nuclear antigen (PCNA) is post-translationally modified by ubiquitin in yeast and mammalian cells. It is widely accepted that in yeast mono- and polyubiquitinated PCNA is involved in distinct pathways of DNA postreplication repair. This study showed an interaction between plant ubiquitin and PCNA in the plant cell. Using different approaches, it was demonstrated that Arabidopsis RAD5a ubiquitin ligase is involved in the post-translational modification of plant PCNA. A detailed analysis of the properties of selected Arabidopsis ubiquitin-conjugating enzymes (AtUBC) has shown that a plant homologue of yeast RAD6 (AtUBC2) is sufficient to monoubiquitinate AtPCNA in the absence of ubiquitin ligase. Using different combinations of selected AtUBC proteins together with AtRAD5a, it was demonstrated that plants have potential to use different pathways to ubiquitinate PCNA. The analysis of Arabidopsis PCNA1 and PCNA2 did not demonstrate substantial differences in the ubiquitination pattern between these two proteins. The major ubiquitination target of Arabidopsis PCNA, conserved in eukaryotes, is lysine 164. Taken together, the presented results clearly demonstrate the involvement of Arabidopsis UBC and RAD5a proteins in the ubiquitination of plant PCNA at lysine 164. The data show the complexity of the plant ubiquitination system and open new questions about its regulation in the plant cell.