The catalytic domain CysPc of the DEK1 calpain is functionally conserved in land plants
The catalytic domain CysPc of the DEK1 calpain is functionally conserved in land plants
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DOI：
10.1111/tpj.12235
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发表时间：
2013-09-01
期刊：
影响因子：
7.2
通讯作者：
Johansen, Wenche
中科院分区：
文献类型：
--
作者：
Liang, Zhe;Demko, Viktor;Johansen, Wenche
DEK 1是陆地植物中唯一的钙蛋白酶，属于TML-CysPc-C2 L钙蛋白酶家族，其历史可追溯到15亿年前。在这里，我们表明，CysPc-C2 L域的陆地植物钙蛋白酶形成一个单独的分支DEK 1进化枝的植物系统发育树。轮藻属中柱藻绿色DEK 1样基因明显不同于陆地植物中的基因，这表明DEK 1在向陆地植物过渡期间发生了重大的进化转变。基于遗传互补的拟南芥dek 1 -3突变体使用CysPc-C2 L结构域的各种来源，我们表明，这两个结构域已在陆地植物中的功能保守至少4.5亿年。这一结论是基于来自藓类小立碗藓的DEK 1的CysPc-C2 L结构域补充拟南芥dek 1 -3突变体表型的观察。相比之下，无论是CysPc-C2 L结构域从绿色支原体或嵌合动物-植物钙蛋白酶补充这个突变体。共进化分析确定了DEK 1和经典钙蛋白酶的CysPc-C2 L残基之间的相互作用的差异，支持这两种酶是由根本不同的机制调节的观点。利用拟南芥DEK 1 -3互补分析，我们表明，4个保守的氨基酸残基的两个钙结合位点的CysPc结构域的经典钙蛋白酶是保守的陆地植物和功能上必不可少的拟南芥DEK 1。
DEK1, the single calpain of land plants, is a member of the ancient membrane bound TML-CysPc-C2L calpain family that dates back 1.5billion years. Here we show that the CysPc-C2L domains of land plant calpains form a separate sub-clade in the DEK1 clade of the phylogenetic tree of plants. The charophycean alga Mesostigma viride DEK1-like gene is clearly divergent from those in land plants, suggesting that a major evolutionary shift in DEK1 occurred during the transition to land plants. Based on genetic complementation of the Arabidopsis thaliana dek1-3 mutant using CysPc-C2L domains of various origins, we show that these two domains have been functionally conserved within land plants for at least 450 million years. This conclusion is based on the observation that the CysPc-C2L domains of DEK1 from the moss Physcomitrella patens complements the A.thaliana dek1-3 mutant phenotype. In contrast, neither the CysPc-C2L domains from M.viride nor chimeric animal-plant calpains complement this mutant. Co-evolution analysis identified differences in the interactions between the CysPc-C2L residues of DEK1 and classical calpains, supporting the view that the two enzymes are regulated by fundamentally different mechanisms. Using the A.thaliana dek1-3 complementation assay, we show that four conserved amino acid residues of two Ca2+-binding sites in the CysPc domain of classical calpains are conserved in land plants and functionally essential in A.thaliana DEK1.