trehalase-2 protein contributes to trehalase activity enhanced by diapause hormone in developing ovaries of the silkworm, Bombyx mori
trehalase-2 protein contributes to trehalase activity enhanced by diapause hormone in developing ovaries of the silkworm, Bombyx mori
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DOI：
10.1016/j.jinsphys.2010.10.001
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发表时间：
2011-05-01
影响因子：
2.2
通讯作者：
Yaginuma, Toshinobu
中科院分区：
文献类型：
--
作者：
Kamei, Yuhki;Hasegawa, Yuh;Yaginuma, Toshinobu
滞育激素是在家蚕中胚层分离完成后，立即以雌蛹发育中的卵巢为靶标，诱导胚胎滞育。同时，水解酶增强卵母细胞膜上海藻糖酶的活性，通过刺激血淋巴海藻糖的掺入，导致卵母细胞中糖原浓度升高。在家蚕中，已分离到编码可溶性海藻糖酶(68 KDa)和整膜海藻糖酶(74 KDa)的Treh-1和-2基因。HD刺激这两个基因的mRNA表达。在这项研究中，我们旨在阐明卵巢海藻糖酶是起源于Treh-1还是Treh-2。对发育中的卵巢进行的免疫印迹显示，无论是非滞育还是滞育的产卵者，在膜结合部分都有阳性条带，含有海藻糖酶活性，只有抗Treh-1&2和Treh-2的抗体，而没有抗Treh-1的抗体。在食道下神经节完整的蛹(SG，唯一的水解氢生物合成器官)和化蛹当天去除食道下神经节(SGS)后，中期注射水解液的幼虫的卵巢中，74 kDa阳性染色条带的强度增加了约4倍。实时荧光定量聚合酶链式反应结果显示，在卵巢发育过程中，每拷贝rp49的Treh-2mRNA拷贝数约为Treh-1mRNA拷贝数的1000倍。这些结果表明，水解酶增强的海藻糖酶活性主要来源于转录水平上调节的Treh-2蛋白。(C)2010爱思唯尔有限公司。保留所有权利。
Diapause hormone (DH) targets developing ovaries in female pupae to induce embryonic diapause immediately after completion of mesoderm segregation of the silkworm, Bombyx mori. At the same time, DH enhances trehalase activity on the oolemma, which leads to higher concentrations of glycogen in oocytes through the stimulated incorporation of hemolymph trehalose. In B. mori, the treh-1 and -2 genes encoding soluble trehalase (68 kDa) and integral-membrane trehalase (74 kDa) have been isolated. DH stimulates mRNA expression of both of these genes. In this study, we aimed to clarify whether ovarian trehalase originates from Treh-1 or Treh-2. Western blotting of the developing ovaries showed positive bands in the membrane-bound fraction, containing trehalase activity, only with antibodies against Treh-1&2 and Treh-2, but not Treh-1, irrespective of nondiapause or diapause egg-producers. The intensities of the positively stained 74 kDa bands were increased approximately 4-fold in ovaries from pupae with intact subesophageal ganglion (SG, a unique DH-biosynthesizing organ), and from pupae that were injected with DH at the middle pupal stage after their SGs were removed on the day of pupation. Furthermore, quantitative real-time PCR data showed that in developing ovaries, copy number of treh-2 mRNA per one copy of rp49 mRNA was approximately 1000-fold higher than that of treh-1 mRNA. These results demonstrate that trehalase activities enhanced by DH originate mainly from treh-2 protein regulated at the transcriptional level. (C) 2010 Elsevier Ltd. All rights reserved.