A vitellogenin chain containing a superoxide dismutase-like domain is the major component of yolk proteins in cladoceran crustacean Daphnia magna
A vitellogenin chain containing a superoxide dismutase-like domain is the major component of yolk proteins in cladoceran crustacean Daphnia magna
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DOI：
10.1016/j.gene.2004.03.030
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发表时间：
2004-06-09
期刊：
影响因子：
3.5
通讯作者：
Yamagata, H
中科院分区：
文献类型：
--
作者：
Kato, Y;Tokishita, S;Yamagata, H
从枝节甲壳动物大型蚤（Daphnia magna）中克隆了一个编码卵黄蛋白原（VTG）的cDNA，该基因是卵黄蛋白（VTN）的前体。DmagVTG 1的氨基酸序列推测为16个氨基酸残基的信号肽序列。DmagVTG 1可能的成熟形式由1985个氨基酸残基组成，计算的分子量为223，070 Da。在许多其他生物体的VTG的氨基酸序列中发现的大脂质转移（LLT）模块和部分von Willebrand因子D（VWD）模块在DmagVTG 1中非常保守。系统发育分析表明，DmagVTG 1的LLT模块与昆虫VTG的关系比与十足目甲壳动物的关系更密切。DmagVTG 1的一个独特特征是在其NH 2末端具有超氧化物歧化酶（SOD）样结构域。分别制备了SOD样结构域、VTG结构域的NH 2-末端部分和VTG结构域的COOH-末端部分的抗血清，并用于D.大卵黄蛋白在D.排卵后立即分离大孤雌生殖卵。配合物IV和V含量最高。DmagVTG 1是复合物III、IV和V的组成部分，是D.大鸡蛋。蛋白质复合物在发育过程中逐渐发生蛋白质水解。切割的主要位点之一是位于DmagVTG 1的第1454位和第1455位的两个连续的Arg残基之间。(C)2004 Elsevier B. V.保留所有权利。
A cDNA encoding vitellogenin (VTG), a precursor of a major yolk protein, vitellin (VTN), was isolated from cladoceran crustacean Daphnia magna. The deduced amino acid sequence of DmagVTG1, the polypeptide encoded by the cDNA, contained a possible signal peptide sequence of 16 amino acid (aa) residues. The possible mature form of DmagVTG1 consists of 1985 aa residues with a calculated molecular mass of 223,070 Da. The large lipid transfer (LLT) module and a part of the von Willebrand factor D (VWD) module found in the aa sequences of VTGs of many other organisms are well conserved in DmagVTG1. Phylogenetic analysis suggested that the LLT module of DmagVTG1 is more closely related to those of insect VTGs than those of decapodan crustaceans. A unique feature of DmagVTG1 is that it has a superoxide dismutase (SOD)-like domain at its NH2-terininus. Antisera against the SOD-like domain, the NH2-terminal part of the VTG domain and the COOH-terminal part of the VTG domain, respectively, were prepared and used for analysis of D. magna yolk proteins. Six species (I to VI) of major protein complexes were found in D. magna parthenogenetic eggs isolated immediately after ovulation. Complexes IV and V were the most abundant. DmagVTG1 was a component of Complexes III, IV and V, and the most abundant polypeptide in D. magna eggs. The protein complexes underwent gradual proteolysis during development. One of the primary sites of cleavage was between the two successive Arg residues located at the 1454th and 1455th positions of DmagVTG1. (C) 2004 Elsevier B.V. All rights reserved.