The function of two type II metacaspases in woody tissues of Populus trees
The function of two type II metacaspases in woody tissues of Populus trees
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DOI：
10.1111/nph.14945
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发表时间：
2018-03-01
期刊：
影响因子：
9.4
通讯作者：
Tuominen, Hannele
中科院分区：
文献类型：
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作者：
Bollhoner, Benjamin;Jokipii-Lukkari, Soile;Tuominen, Hannele
Metacaspases（MC）是一种半胱氨酸蛋白酶，参与植物细胞的程序性死亡。AtMC 9（Arabidopsis thaliana Metacaspase 9）是拟南芥MC家族的成员，控制木质部导管分子的快速自溶，但其下游靶基因在木质部中的作用尚不清楚，PttMC 13和PttMC 14在杂种白杨中被鉴定为AtMC 9同源基因。对转基因杂种白杨树木质部组织进行了蛋白质组学分析，这些转基因杂种树携带了PttMC 13和PttMC 14的过表达或RNA干扰构建体。蛋白质组学分析显示，先前已知的两种后半胱氨酸蛋白酶靶点，如Tudor葡萄球菌核酸酶、热休克蛋白和14-3-3蛋白，以及新蛋白，如假定天冬氨酸蛋白酶3（PASPA 3）和半胱氨酸蛋白酶RD 21的同源物。我们在此鉴定了在木质部组织中由PttMC 13和PttMC 14调节的途径和过程。特别地，结果表明PttMC 13和/或PttMC 14参与木质部元件的下游蛋白水解过程和细胞死亡。这项工作为今后的功能和生化分析提供了一个有价值的参考数据集木细胞特异性metacaspase功能。
Metacaspases (MCs) are cysteine proteases that are implicated in programmed cell death of plants. AtMC9 (Arabidopsis thaliana Metacaspase9) is a member of the Arabidopsis MC family that controls the rapid autolysis of the xylem vessel elements, but its downstream targets in xylem remain uncharacterized.PttMC13 and PttMC14 were identified as AtMC9 homologs in hybrid aspen (Populustremulaxtremuloides). A proteomic analysis was conducted in xylem tissues of transgenic hybrid aspen trees which carried either an overexpression or an RNA interference construct for PttMC13 and PttMC14.The proteomic analysis revealed modulation of levels of both previously known targets of metacaspases, such as Tudor staphylococcal nuclease, heat shock proteins and 14-3-3 proteins, as well as novel proteins, such as homologs of the PUTATIVE ASPARTIC PROTEASE3 (PASPA3) and the cysteine protease RD21 by PttMC13 and PttMC14.We identified here the pathways and processes that are modulated by PttMC13 and PttMC14 in xylem tissues. In particular, the results indicate involvement of PttMC13 and/or PttMC14 in downstream proteolytic processes and cell death of xylem elements. This work provides a valuable reference dataset on xylem-specific metacaspase functions for future functional and biochemical analyses.