Polyphosphate goes from pedestrian to prominent in the marine P-cycle
Polyphosphate goes from pedestrian to prominent in the marine P-cycle
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聚磷酸盐从平淡无奇到在海洋 P 循环中占据重要地位
DOI：
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发表时间：
2014
影响因子：
11.1
通讯作者：
K. Björkman
中科院分区：
文献类型：
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作者：
K. Björkman
磷在所有生命中起着关键作用（1），从提供运行细胞机器的能量，连接形成生命“蓝图”的RNA和DNA中的核苷酸，到成为细胞膜脂质双层的组成部分，通过划分生化过程使生命成为可能。聚磷酸盐（poly-P）是由几个到数百个磷酸盐分子组成的线性或环状聚合物，这些磷酸盐分子与ATP中发现的相同类型的高能键相连，ATP是活细胞内能量交易的关键分子，而聚磷酸盐实际上可以在某些酶促反应中作为ATP的替代品（2）。Poly-P最有可能存在于地球历史的前生物时代，因为这些聚合物在火山或热液喷口活动期间自发形成（3）。此外，有人推测聚磷可能在我们星球上生命的起源中发挥了作用（4）。虽然聚-P似乎在整个自然界中无处不在（5），并且长期以来一直被认为是磷酸盐的储存分子，但直到最近，人们对其在细胞中的作用和功能知之甚少（6）。因此，聚-P有时被称为分子“化石”（7），因为它在细胞代谢中的作用模糊且可能是行人，因此在过去没有引起太多的科学兴趣。然而，在过去的几十年里，越来越清楚的是，聚P可能实际上对多种细胞功能至关重要，包括但不限于基因表达调控、能量储存、运动性以及最终的细胞存活（4）。然而，聚磷在海洋环境中及其微生物居民的存在，分布和意义在很大程度上缺乏，尽管最近的宏基因组研究表明它们对贫营养海洋中的微生物具有潜在的重要性（8）。在此，Martin等人（9）介绍了迄今为止对海洋环境中颗粒物质中聚磷含量和分布的最全面研究。他们的研究横切了营养物质相对丰富的温带北大西洋西部（TWNA）海洋，穿过墨西哥湾流，进入磷严重受限的亚热带马尾藻海。沿着这条断面提供了营养状况的自然梯度，他们测量了上层水柱中微生物群落的多聚磷含量以及其他与磷有关的参数，以及从上层海洋沉入其深层内部的颗粒中多聚磷的含量。
Phosphorus plays a key role in all life (1), from providing the energy that runs the cell machinery, linking nucleotides in RNA and DNA that form the “blueprint” of life, to being an integral part of the cell membrane lipid bilayer, making life possible by compartmentalizing biochemical processes. Polyphosphates (poly-P) are linear or cyclical polymers of a few to many hundreds of phosphate molecules linked with the same type of high-energy bond found in ATP, the key molecule in energy transactions within living cells, and poly-P may in fact act as a substitute for ATP in some enzymatic reactions (2). Poly-P was most likely present in prebiological times of the Earth’s history as these polymers spontaneously form during volcanic, or hydrothermal vent, activity (3). Additionally, it has been speculated that poly-P may have played a role in the origins of life on our planet (4). Although, poly-P appears to be ubiquitous throughout the natural world (5) and has long been recognized as a storage molecule for phosphate, relatively little has been known about its role and function in cells until quite recently (6). As a result, poly-P has sometimes been called a molecular “fossil” (7) due to its obscure and presumably pedestrian role in cell metabolism and hence has not garnered much scientific interest in the past. Nevertheless, over the last decades, it has become increasingly clear that poly-P may in fact be essential for a multitude of cellular functions, including, but not limited to, gene expression regulation, energy storage, motility, and ultimately the survival of the cell (4). However, the presence, distribution, and significance of poly-P in the marine environment and to its microbial inhabitants have been largely lacking, although recent metagenomic studies have suggested their potential importance to microorganisms in the oligotrophic oceans (8). Here, Martin et al. (9) present, to date, the most comprehensive study of poly-P content and distribution in particulate material in the marine environment. Their study transects the temperate western North Atlantic (TWNA) Ocean, which is relatively rich in nutrients, across the Gulf Stream and into the severely phosphorus-limited subtropical Sargasso Sea. Along this transect, which provides a natural gradient in nutrient regimes, they measure the poly-P content, among other phosphorus-relevant parameters, of the microbial communities in the upper water column, as well as the amount of poly-P in particles sinking out of the upper ocean into its deep interior.