Arabidopsis NIP2;1, a major intrinsic protein transporter of lactic acid induced by anoxic stress
Arabidopsis NIP2;1, a major intrinsic protein transporter of lactic acid induced by anoxic stress
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DOI：
10.1074/jbc.m700982200
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发表时间：
2007-08-17
影响因子：
4.8
通讯作者：
Roberts, Daniel M.
中科院分区：
文献类型：
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作者：
Choi, Won-Gyu;Roberts, Daniel M.
结瘤素26内在蛋白（NIPs）是植物特异性的、高度保守的水和溶质转运蛋白，与大豆结瘤素26具有结构和功能同源性。拟南芥含有9个NIP基因。在这项研究中，它表明，其中之一，AtNIP 2; 1，是非常敏感的水涝和缺氧胁迫。基于定量PCR和启动子：：GUS实验，AtNIP 2; 1在分化根的根尖和维管束中以低基础水平表达。根或叶组织的水涝后，转录物水平急剧且迅速升高，在浸没的第1小时内根中增加70倍。在这种大的初始增加之后，mRNA水平下降到稳定状态水平，其在浸没后6小时保持超过10倍。一个更大的诱导AtNIP 2; 1的表达后观察到的拟南芥幼苗缺氧的挑战，与AtNIP 2; 1的转录增加了300倍，观察到2小时后开始缺氧。AtNIP 2的功能分析1在非洲爪蟾卵母细胞中表达的结果表明，该蛋白质不同于大豆甜蛋白26，表现出最小的水和甘油转运。相反，AtNIP 2; 1显示乳酸的运输，优先选择这种弱酸的质子化酸性形式。总体而言，数据表明AtNIP 2; 1是编码乳酸转运蛋白的厌氧诱导基因，并且可能在厌氧应激下适应乳酸发酵中发挥作用。
Nodulin 26 intrinsic proteins ( NIPs) are plant- specific, highly conserved water and solute transport proteins with structural and functional homology to soybean nodulin 26. Arabidopsis thaliana contains nine NIP genes. In this study, it is shown that one of these, AtNIP2; 1, is exquisitely sensitive to water logging and anoxia stress. Based on quantitative PCR and promoter:: GUS experiments, AtNIP2; 1 is expressed at a low basal level in the root tips and the vascular bundle of differentiated roots. Transcript levels are elevated acutely and rapidly upon water logging of root or leaf tissues, increasing 70- fold in roots within the 1st h of submersion. After this large initial increase, mRNA levels decline to steady state levels that remain over 10- fold higher by 6 h post- submersion. An even greater induction of AtNIP2; 1 expression was observed upon anoxia challenge of Arabidopsis seedlings, with a 300- fold increase in AtNIP2; 1 transcript observed by 2 h after the initiation of oxygen deprivation. Functional analysis of AtNIP2; 1 expressed in Xenopus oocytes shows that the protein differs from soybean nodulin 26, showing minimal water and glycerol transport. Instead, AtNIP2; 1 displays transport of lactic acid, with a preference for the protonated acidic form of this weak acid. Overall, the data suggest that AtNIP2; 1 is an anaerobic- induced gene that encodes a lactic acid transporter and may play a role in adaptation to lactic fermentation under anaerobic stress.