Genome-Wide Characterization of Major Intrinsic Proteins in Four Grass Plants and Their Non-Aqua Transport Selectivity Profiles with Comparative Perspective.
Genome-Wide Characterization of Major Intrinsic Proteins in Four Grass Plants and Their Non-Aqua Transport Selectivity Profiles with Comparative Perspective.
复制标题
四种草植物中主要的内在蛋白质及其非Aqua转运选择性谱的全基因组表征，具有比较的透视。
DOI：
10.1371/journal.pone.0157735
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Katsuhara M
中科院分区：
文献类型：
--
作者：
Azad AK;Ahmed J;Alum MA;Hasan MM;Ishikawa T;Sawa Y;Katsuhara M
主要内在蛋白（Major intrinsic proteins, MIPs）通常被称为水通道蛋白（aquaporins），它不仅运输植物体内的水分，还运输其他具有生理意义的底物和重金属。在大多数高等植物中，MIPs可分为5个亚科（PIPs、TIPs、NIPs、SIPs和XIPs）。在四种单子草植物中分别鉴定出68个、42个、38个和28个全长MIPs，分别是Panicum virgatum、Setaria italica、Sorghum bicolor和Brachypodium distachyon。系统发育分析表明，禾本科植物仅有PIPs、TIPs、NIPs和不含XIPs的SIPs 4个MIP亚科。基于同源模型的结构分析，并比较了所有已被实验证明能够运输非水底物的植物MIPs的主要选择性相关基序[两个NPA区，芳香/精氨酸（ar/R）选择性过滤器和Froger位置（FPs）]，我们预测了所有MIPs在四种禾草植物和其他八种植物中的运输谱。基于ar/R选择性过滤器和FPs的MIP亚族群与非水转运谱有关。我们进一步破译了四种禾本科植物中MIPs的底物选择性谱，并将其与水稻、玉米、大豆、杨树、棉花、拟南芥、小立碗菌和卷柏的同类底物选择性谱进行了比较。除了两个NPA区域，ar/R过滤器和FPs，某些残基，特别是环路B和C中的残基，有助于MIP群的功能独特性。转录本在不同器官中的表达分析表明，非水转运与MIPs的表达有关，因为大多数未表达的MIPs无法促进非水分子的转运。在所有植物的MIPs中，TIP （BdTIP1;1、SiTIP1;2、SbTIP2；1和PvTIP1；2）的总体平均表达量最高。我们的研究为了解植物MIPs的多样性、进化、非水转运谱和比较转运选择性提供了重要信息，并为转基因植物的开发提供了工具。
Major intrinsic proteins (MIPs), commonly known as aquaporins, transport not only water in plants but also other substrates of physiological significance and heavy metals. In most of the higher plants, MIPs are divided into five subfamilies (PIPs, TIPs, NIPs, SIPs and XIPs). Herein, we identified 68, 42, 38 and 28 full-length MIPs, respectively in the genomes of four monocot grass plants, specifically Panicum virgatum, Setaria italica, Sorghum bicolor and Brachypodium distachyon. Phylogenetic analysis showed that the grass plants had only four MIP subfamilies including PIPs, TIPs, NIPs and SIPs without XIPs. Based on structural analysis of the homology models and comparing the primary selectivity-related motifs [two NPA regions, aromatic/arginine (ar/R) selectivity filter and Froger's positions (FPs)] of all plant MIPs that have been experimentally proven to transport non-aqua substrates, we predicted the transport profiles of all MIPs in the four grass plants and also in eight other plants. Groups of MIP subfamilies based on ar/R selectivity filter and FPs were linked to the non-aqua transport profiles. We further deciphered the substrate selectivity profiles of the MIPs in the four grass plants and compared them with their counterparts in rice, maize, soybean, poplar, cotton, Arabidopsis thaliana, Physcomitrella patens and Selaginella moellendorffii. In addition to two NPA regions, ar/R filter and FPs, certain residues, especially in loops B and C, contribute to the functional distinctiveness of MIP groups. Expression analysis of transcripts in different organs indicated that non-aqua transport was related to expression of MIPs since most of the unexpressed MIPs were not predicted to facilitate the transport of non-aqua molecules. Among all MIPs in every plant, TIP (BdTIP1;1, SiTIP1;2, SbTIP2;1 and PvTIP1;2) had the overall highest mean expression. Our study generates significant information for understanding the diversity, evolution, non-aqua transport profiles and insight into comparative transport selectivity of plant MIPs, and provides tools for the development of transgenic plants.