ICE‐BINDING PROTEINS FROM SEA ICE DIATOMS (BACILLARIOPHYCEAE) 1
ICE‐BINDING PROTEINS FROM SEA ICE DIATOMS (BACILLARIOPHYCEAE) 1
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来自海冰硅藻（硅藻纲）的冰结合蛋白 1
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
J. Raymond
中科院分区：
文献类型：
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作者：
M. Janech;A. Krell;T. Mock;Jae;J. Raymond
海冰硅藻在低温和高盐度的条件下茁壮成长，因此负责极地光合作用的重要部分。它们的成功可能部分归功于大分子的分泌，这些大分子以前被证明可以干扰冰的生长，并具有作为冷冻保护剂的能力。在这里，我们表明，这些分子之一，由海冰硅藻Navicula glaciei Vankirk产生，是一个25kDa的冰结合蛋白（IBP）。 从另一种海冰硅藻Fragilariopsis cylindrus格鲁诺获得的cDNA编码的蛋白质与部分测序的N. glaciei IBP，并使扩增和测序的N. glaciei IBP cDNA。类似的蛋白质并不存在于嗜温硅藻Thalassiosira dangerana的基因组中。这两种蛋白质非常类似于来自嗜冷雪霉菌的抗冻蛋白，并且作为一个群体代表了一类新的IBP，与鱼类，昆虫和植物以及细菌中发现的其他IBP不同。硅藻的IBPs也与三种原核假设的蛋白质有惊人的相似之处。在海冰中发现了雪霉菌和两种原核生物的亲属，这增加了硅藻IBPs起源于真菌或细菌的可能性。
Sea ice diatoms thrive under conditions of low temperature and high salinity, and as a result are responsible for a significant fraction of polar photosynthesis. Their success may be owing in part to secretion of macromolecules that have previously been shown to interfere with the growth of ice and to have the ability to act as cryoprotectants. Here we show that one of these molecules, produced by the sea ice diatom Navicula glaciei Vanheurk, is a ∼25 kDa ice‐binding protein (IBP). A cDNA obtained from another sea ice diatom, Fragilariopsis cylindrus Grunow, was found to encode a protein that closely matched the partially sequenced N. glaciei IBP, and enabled the amplification and sequencing of an N. glaciei IBP cDNA. Similar proteins are not present in the genome of the mesophilic diatom Thalassiosira pseudonana. Both proteins closely resemble antifreeze proteins from psychrophilic snow molds, and as a group represent a new class of IBPs that is distinct from other IBPs found in fish, insects and plants, and bacteria. The diatom IBPs also have striking similarities to three prokaryotic hypothetical proteins. Relatives of both snow molds and two of the prokaryotes have been found in sea ice, raising the possibility of a fungal or bacterial origin of diatom IBPs.