Biocenter Klein Flottbek, University of Hamburg, Hamburg, Germany.
Antioxid Redox Signal. 2013 Jun 1;18(16):2163-83. doi: 10.1089/ars.2012.5130. Epub 2013 Feb 28.
Several redox compounds, including respiratory burst oxidase homologs (Rboh) and iron chelate reductases have been identified in animal and plant plasma membrane (PM). Studies using molecular biological, biochemical, and proteomic approaches suggest that PM redox systems of plants are involved in signal transduction, nutrient uptake, transport, and cell wall-related processes. Function of PM-bound redox systems in oxidative stress will be discussed.
Present knowledge about the properties, structures, and functions of these systems are summarized. Judging from the currently available data, it is likely that electrons are transferred from cytosolic NAD(P)H to the apoplast via quinone reductases, vitamin K, and a cytochrome b561. In tandem with these electrons, protons might be transported to the apoplastic space.
Recent studies suggest localization of PM-bound redox systems in microdomains (so-called lipid or membrane rafts), but also organization of these compounds in putative and high molecular mass protein complexes. Although the plant flavocytochrome b family is well characterized with respect to its function, the molecular mechanism of an electron transfer reaction by these compounds has to be verified. Localization of Rboh in other compartments needs elucidation.
Plant members of the flavodoxin and flavodoxin-like protein family and the cytochrome b561 protein family have been characterized on the biochemical level, postulated localization, and functions of these redox compounds need verification. Compositions of single microdomains and interaction partners of PM redox systems have to be elucidated. Finally, the hypothesis of an electron transfer chain in the PM needs further proof.
几种氧化还原化合物，包括呼吸爆发氧化还原酶同源物（Rboh）和铁螯合还原酶，已在动物和植物质膜（PM）中被鉴定。使用分子生物学、生物化学和蛋白质组学方法的研究表明，植物的 PM 氧化还原系统参与信号转导、营养物质吸收、运输和细胞壁相关过程。将讨论 PM 结合的氧化还原系统在氧化应激中的功能。
总结了这些系统的性质、结构和功能的现有知识。根据目前可用的数据，电子很可能通过醌还原酶、维生素 K 和细胞色素 b561 从胞质 NAD(P)H 转移到质外体。与这些电子一起，质子可能被转运到质外空间。
最近的研究表明 PM 结合的氧化还原系统定位于微区（所谓的脂质或膜筏），但也存在于假定的和高分子质量蛋白复合物中的这些化合物的组织。尽管植物黄素细胞色素 b 家族在其功能方面得到了很好的描述，但这些化合物的电子转移反应的分子机制仍需验证。Rboh 在其他隔室中的定位需要阐明。
已经在生化水平上对植物黄素蛋白和黄素蛋白样蛋白家族以及细胞色素 b561 蛋白家族的成员进行了表征，这些氧化还原化合物的假定定位和功能需要验证。单个微区的组成和 PM 氧化还原系统的相互作用伙伴必须阐明。最后，PM 中电子转移链的假设需要进一步证明。
