Multiple vitellogenins and their unique roles in marine teleosts
Multiple vitellogenins and their unique roles in marine teleosts
复制标题
DOI：
10.1023/b:fish.0000030559.71954.37
复制
发表时间：
2003-01-01
影响因子：
2.9
通讯作者：
Hara, A
中科院分区：
文献类型：
--
作者：
Matsubara, T;Nagae, M;Hara, A
卵黄蛋白原（Vitellogenin，Vg）是硬骨鱼类卵黄蛋白的前体，包括卵黄脂蛋白（lipovitellin，Lv）、卵黄蛋白质（acetavitin，Pv）和β '-组分（beta'-c）。完整的Vg分子含有以线性方式排列的卵黄蛋白结构域：NH 2-Lv重链、Pv、Lv轻链、β '-c、C-末端编码区（C-t）-COOH。免疫印迹法采用抗血清提出了对重组C-t多肽显示，Vg的C-t结构域引起的第四个蛋黄蛋白在barfin比目鱼卵母细胞。在硬骨鱼中存在三类Vg，包括两种类型的完整Vg（A型和B型）和一种较小的、不完整的Vg，缺乏Pv结构域（Pv-less型）。通过对几种硬骨鱼类中每种类型的Vg转录本的不同区域扩增的cDNA进行测序，我们发现高等分类群的成员（例如，副棘鳍鱼和棘鳍鱼）同时表达Vg A和Vg B，并且不含PV的Vg广泛存在于硬骨鱼类中。卵黄原蛋白A和B通过选择性地水解卵母细胞中的卵黄蛋白，在调节巴氏拟庸鲽卵的浮力中发挥不同的作用。蛋白酶的规范程序证实参与组织蛋白酶B样酶在这成熟相关的蛋白水解。pH值变化的测量表明，激烈的酸化的卵质伴随着水解的蛋黄蛋白。因此，相对于卵黄蛋白水解和卵母细胞水合，细胞质成熟似乎是通过改变成熟卵母细胞的pH值来控制的。
Vitellogenin (Vg) is the precursor to egg yolk proteins of teleost fishes, including lipovitellin (Lv), phosvitin (Pv), and beta'-component (beta'-c). Complete Vg molecules contain the yolk protein domains arranged in linear fashion: NH2-Lv heavy chain, Pv, Lv light chain, beta'-c, C-terminal coding region (C-t)-COOH. Western blots employing an antiserum raised against a recombinant C-t polypeptide revealed that the C-t domain of Vg gives rise to a fourth yolk protein in barfin flounder oocytes. Three classes of Vg appear to exist in teleosts, including two types of complete Vg (A-type and B-type) and a smaller, incomplete Vg lacking a Pv domain (Pv-less type). By sequencing cDNA amplified from distinctive regions of each type of Vg transcript from several teleosts, we discovered that members of higher taxa (e.g. Paracanthopterygii and Acanthopterygii) express both Vg A and Vg B, and that Pv-less Vg is widely present among teleosts. Vitellogenins A and B play distinct roles in regulation of egg buoyancy in barfin flounder through selective proteolysis of their product yolk proteins in oocytes undergoing final maturation. Protease specification procedures confirmed involvement of a cathepsin B-like enzyme in this maturation-associated proteolysis. Measurement of changing pH revealed that drastic acidification of the ooplasm accompanies hydrolysis of the yolk proteins. Thus, with respect to yolk protein hydrolysis and oocyte hydration, cytoplasmic maturation appears to be controlled by changing pH in maturing oocytes.