Geminivirus Infection Up-Regulates the Expression of Two Arabidopsis Protein Kinases Related to Yeast SNF1- and Mammalian AMPK-Activating Kinases1
Geminivirus Infection Up-Regulates the Expression of Two Arabidopsis Protein Kinases Related to Yeast SNF1- and Mammalian AMPK-Activating Kinases1
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DOI：
10.1104/pp.106.088476
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发表时间：
2006-10
期刊：
影响因子：
7.4
通讯作者：
W. Shen;L. Hanley-Bowdoin
中科院分区：
文献类型：
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作者：
W. Shen;L. Hanley-Bowdoin
双生病毒Rep相互作用激酶1（GRIK 1）和GRIK 2构成拟南芥（Arabidopsis thaliana）中的小蛋白激酶家族。早期的研究表明，GRIK 1的截短版本与双生病毒复制蛋白AL 1结合。我们在这里展示了在酵母双杂交研究中全长GRIK 1和GRIK 2与AL 1相互作用。使用特异性抗体，我们发现，这两个拟南芥激酶升高在受感染的叶片。健康植物的免疫印迹分析显示GRIK 1和GRIK 2在幼叶和花组织中最高，在成熟组织中较低或检测不到。免疫组织化学染色显示，激酶积累在茎尖分生组织，叶原基，和新兴的叶柄。与蛋白质模式不同，GRIK 1和GRIK 2转录水平在感染期间仅显示出小幅增加，并且在发育期间不会发生显著变化。用蛋白酶体抑制剂MG 132处理健康幼苗和受感染的叶片导致GRIK 1和GRIK 2蛋白水平较高，而用翻译抑制剂放线菌酮处理则降低了这两种激酶，表明它们的积累是由转录后过程调节的。系统发育比较表明，GRIK 1，GRIK 2，和相关的激酶从蒺藜苜蓿和水稻（水稻）是最相似的酵母激酶PAK 1，TOS 3，ELM 1和哺乳动物激酶CaMKK，激活酵母激酶SNF 1和其哺乳动物同源AMPK，分别。使用PAK 1/TOS 3/ELM 1三重突变体的互补研究表明GRIK 1和GRIK 2可以在功能上取代酵母激酶，表明拟南芥激酶通过激活SNF 1相关激酶介导早期植物发育和双生病毒感染期间的一个或多个过程。
Geminivirus Rep-interacting kinase 1 (GRIK1) and GRIK2 constitute a small protein kinase family in Arabidopsis (Arabidopsis thaliana). An earlier study showed that a truncated version of GRIK1 binds to the geminivirus replication protein AL1. We show here both full-length GRIK1 and GRIK2 interact with AL1 in yeast two-hybrid studies. Using specific antibodies, we showed that both Arabidopsis kinases are elevated in infected leaves. Immunoblot analysis of healthy plants revealed that GRIK1 and GRIK2 are highest in young leaf and floral tissues and low or undetectable in mature tissues. Immunohistochemical staining showed that the kinases accumulate in the shoot apical meristem, leaf primordium, and emerging petiole. Unlike the protein patterns, GRIK1 and GRIK2 transcript levels only show a small increase during infection and do not change significantly during development. Treating healthy seedlings and infected leaves with the proteasome inhibitor MG132 resulted in higher GRIK1 and GRIK2 protein levels, whereas treatment with the translation inhibitor cycloheximide reduced both kinases, demonstrating that their accumulation is modulated by posttranscriptional processes. Phylogenetic comparisons indicated that GRIK1, GRIK2, and related kinases from Medicago truncatula and rice (Oryza sativa) are most similar to the yeast kinases PAK1, TOS3, and ELM1 and the mammalian kinase CaMKK, which activate the yeast kinase SNF1 and its mammalian homolog AMPK, respectively. Complementation studies using a PAK1/TOS3/ELM1 triple mutant showed that GRIK1 and GRIK2 can functionally replace the yeast kinases, suggesting that the Arabidopsis kinases mediate one or more processes during early plant development and geminivirus infection by activating SNF1-related kinases.