A model for carbohydrate metabolism in the diatom Phaeodactylum tricornutum deduced from comparative whole genome analysis.
A model for carbohydrate metabolism in the diatom Phaeodactylum tricornutum deduced from comparative whole genome analysis.
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DOI：
10.1371/journal.pone.0001426
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发表时间：
2008-01-09
期刊：
影响因子：
3.7
通讯作者：
Bowler C
中科院分区：
文献类型：
--
作者：
Kroth PG;Chiovitti A;Gruber A;Martin-Jezequel V;Mock T;Parker MS;Stanley MS;Kaplan A;Caron L;Weber T;Maheswari U;Armbrust EV;Bowler C
硅藻是单细胞藻类，约占全球碳固定的20%。与具有原始质体的藻类相比，它们通过二次内共生进化，形成了复杂的细胞结构和新陈代谢。
三角褐指藻的全基因组序列最近已完成。我们基于大量的表达序列标签（EST）支持以及与另一种硅藻——假微型海链藻的全基因组序列比较，对参与碳水化合物代谢途径的酶的基因进行了鉴定和注释。根据与其他真核生物线粒体定位基序的相似性确定，预测蛋白质定位于线粒体，而蛋白质定位于质体是基于信号肽基序的存在以及先前在硅藻中显示为必需的质体定位基序。我们在三角褐指藻中鉴定出可能参与类似C4光合作用的基因，并根据相关蛋白质基于序列的假定定位，讨论了这两种硅藻在碳浓缩机制和二氧化碳固定方面可能存在的差异。我们还鉴定出编码参与光呼吸的酶的基因，但有一个有趣的例外：在三角褐指藻和假微型海链藻中均未发现甘油酸激酶。多种卡尔文循环酶以多达五种不同的同工酶形式存在，分布于质体、线粒体和细胞质中。硅藻将能量以脂质或金藻昆布糖（一种β -1,3 - 葡聚糖）的形式储存在质体之外。我们鉴定出多种β - 葡聚糖酶和大型膜结合葡聚糖合酶。有趣的是，大多数葡聚糖酶似乎含有C末端锚定结构域，这些结构域可能使酶附着于膜上。
在此，我们基于假微型海链藻和三角褐指藻的基因组序列，详细阐述了硅藻的碳水化合物代谢。该模型为两种不同硅藻对溶解无机碳的获取以及碳的主要代谢途径提供了新的见解，这对于更好地理解全球碳循环具有重要意义。
Diatoms are unicellular algae responsible for approximately 20% of global carbon fixation. Their evolution by secondary endocytobiosis resulted in a complex cellular structure and metabolism compared to algae with primary plastids. The whole genome sequence of the diatom Phaeodactylum tricornutum has recently been completed. We identified and annotated genes for enzymes involved in carbohydrate pathways based on extensive EST support and comparison to the whole genome sequence of a second diatom, Thalassiosira pseudonana. Protein localization to mitochondria was predicted based on identified similarities to mitochondrial localization motifs in other eukaryotes, whereas protein localization to plastids was based on the presence of signal peptide motifs in combination with plastid localization motifs previously shown to be required in diatoms. We identified genes potentially involved in a C4-like photosynthesis in P. tricornutum and, on the basis of sequence-based putative localization of relevant proteins, discuss possible differences in carbon concentrating mechanisms and CO2 fixation between the two diatoms. We also identified genes encoding enzymes involved in photorespiration with one interesting exception: glycerate kinase was not found in either P. tricornutum or T. pseudonana. Various Calvin cycle enzymes were found in up to five different isoforms, distributed between plastids, mitochondria and the cytosol. Diatoms store energy either as lipids or as chrysolaminaran (a β-1,3-glucan) outside of the plastids. We identified various β-glucanases and large membrane-bound glucan synthases. Interestingly most of the glucanases appear to contain C-terminal anchor domains that may attach the enzymes to membranes. Here we present a detailed synthesis of carbohydrate metabolism in diatoms based on the genome sequences of Thalassiosira pseudonana and Phaeodactylum tricornutum. This model provides novel insights into acquisition of dissolved inorganic carbon and primary metabolic pathways of carbon in two different diatoms, which is of significance for an improved understanding of global carbon cycles.
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影响因子：
6.9
作者：
Badger, MR;Price, GD;Woodger, FJ
通讯作者：
Woodger, FJ
影响因子：
56.9
作者：
Armbrust, EV;Berges, JA;Rokhsar, DS
通讯作者：
Rokhsar, DS
影响因子：
64.8
作者：
Behrenfeld, MJ;Bale, AJ;Falkowski, PG
通讯作者：
Falkowski, PG
DOI：
10.1039/jr9650007035
发表时间：
1965-01-01
期刊：
JOURNAL OF THE CHEMICAL SOCIETY
影响因子：
--
作者：
FORD, CW;PERCIVAL, E
通讯作者：
PERCIVAL, E
影响因子：
6.9
作者：
Fey, V;Wagner, R;Pfannschmidt, T
通讯作者：
Pfannschmidt, T