Molecular characterisation of a candidate gut sucrase in the pea aphid, Acyrthosiphon pisum
Molecular characterisation of a candidate gut sucrase in the pea aphid, Acyrthosiphon pisum
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DOI：
10.1016/j.ibmb.2006.12.005
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发表时间：
2007-04-01
影响因子：
3.8
通讯作者：
Douglas, A. E.
中科院分区：
文献类型：
--
作者：
Price, D. R. G.;Karley, A. J.;Douglas, A. E.
蔗糖是蚜虫的主要膳食碳源，其水解是由肠道 α-葡萄糖苷酶/转葡萄糖苷酶活性催化的。通过基因组和蛋白质组学技术的结合，在豌豆蚜 Acyrthosiphon pisum 肠道的肠道特异性 cDNA 文库和富含蔗糖酶的膜制剂中鉴定出一种被称为 APS1 的 α-葡萄糖苷酶。 APS1 含有预测的信号肽，预测的分子量为 68 kDa（未加工）或 66.4 kDa（成熟蛋白）。它与其他昆虫中糖苷水解酶家族 13 的 α-葡萄糖苷酶 (EC 3.2.1.20) 具有氨基酸序列相似性。预测的 APS1 蛋白包含两个结构域：N 端催化结构域和 C 端疏水结构域。原位定位和 RT-PCR 研究表明，APS1 mRNA 在胃远端的肠道中表达，与蔗糖酶活性的定位相同。当在非洲爪蟾胚胎中异源表达时，APS1 是膜结合的并具有蔗糖酶活性。结论是 APS1 是蚜虫肠道中主要的、也可能是唯一的介导蔗糖酶活性的蛋白质。 (c) 2007 年，爱思唯尔有限公司出版。
The hydrolysis of sucrose, the principal dietary source of carbon for aphids, is catalysed by a gut alpha-glucosidase/transglucosidase activity. An alpha-glucosidase, referred to as APS1, was identified in both a gut-specific cDNA library and a sucrase-enriched membrane preparation from guts of the pea aphid Acyrthosiphon pisum by a combination of genomic and proteomic techniques. APS1 contains a predicted signal peptide, and has a predicted molecular mass of 68 kDa (unprocessed) or 66.4 kDa (mature protein). It has amino acid sequence similarity to alpha-glucosidases (EC 3.2.1.20) of glycoside hydrolase family 13 in other insects. The predicted APS1 protein contains two domains: an N-terminal catalytic domain, and a C-terminal hydrophobic domain. In situ localisation and RT-PCR studies revealed that APS1 mRNA was expressed in the gut distal to the stomach, the same localisation as sucrase activity. When expressed heterologously in Xenopus embryos, APS1 was membrane-bound and had sucrase activity. It is concluded that APS1 is a dominant, and possibly sole, protein mediating sucrase activity in the aphid gut. (c) 2007 Published by Elsevier Ltd.