Isolation and characterization of a new DUR3-like gene, PyDUR3.3, from the marine macroalga Pyropia yezoensis (Rhodophyta)
Isolation and characterization of a new DUR3-like gene, PyDUR3.3, from the marine macroalga Pyropia yezoensis (Rhodophyta)
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DOI：
10.1007/s12562-015-0947-7
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发表时间：
2016-01-01
影响因子：
1.9
通讯作者：
Mikami, Koji
中科院分区：
文献类型：
--
作者：
Kakinuma, Makoto;Suzuki, Kohei;Mikami, Koji
DUR3蛋白介导外源和内源尿素的高亲和力运输。虽然在yezoensis中已经鉴定出两个dur3样基因（PyDUR3.1/3.2），但利用这些序列对P. yezoensis EST数据库进行BLAST搜索表明存在另一个dur3样基因（PyDUR3.3）。本研究分离并鉴定了PyDUR3.3基因，并与PyDUR3.1/3.2基因进行了比较。PyDUR3.3全长679个氨基酸，包含15个跨膜结构域。对藻类、植物和酵母DUR3蛋白的氨基酸序列比对表明，PyDUR3.3与PyDUR3.2的相似性高于其他DUR3蛋白，包括PyDUR3.1。PyDUR3.3和PyDUR3.2的外显子-内含子结构也密切相关，与PyDUR3.1有明显区别。表达分析表明，与配子体相比，无论营养条件如何，孢子体中PyDUR3.3 mRNA的表达水平都非常高。另一方面，PyDUR3.2和PyDUR3.1分别在配子体和孢子体中高表达，并由营养饥饿诱导。这些结果表明，PyDUR3.3/3.2/3.1的表达取决于生活史阶段和营养条件，PyDUR3.3和PyDUR3.2是在功能和生活史阶段特异性分化的同源物。
DUR3 proteins mediate high-affinity transport of exogenous and endogenous urea. Although two DUR3-like genes (PyDUR3.1/3.2) have been identified in Pyropia yezoensis, a BLAST search using these sequences against the P. yezoensis EST database suggested the existence of another DUR3-like gene (PyDUR3.3). In this study, the PyDUR3.3 gene was isolated and characterized and compared to PyDUR3.1/3.2 genes. The predicted length of PyDUR3.3 was 679 amino acids, which included 15 transmembrane domains. An amino acid sequence alignment of algal, plant, and yeast DUR3 proteins showed that PyDUR3.3 was more similar to PyDUR3.2 than to other DUR3 proteins, including PyDUR3.1. Exon-intron structures of PyDUR3.3 and PyDUR3.2 were also closely related to each other, which clearly differed from that of PyDUR3.1. Expression analysis showed that PyDUR3.3 mRNA levels were extremely high in sporophytes, regardless of the nutrient condition, compared to gametophytes. On the other hand, expression of PyDUR3.2 and PyDUR3.1 was high in the gametophytes and sporophytes, respectively, and was induced by nutrient starvation. These results suggest that expression of PyDUR3.3/3.2/3.1 depends on the life history phase as well as the nutrient conditions, and that PyDUR3.3 and PyDUR3.2 are paralogues specifically differentiated in function and life history phase.