Molecular characterization of the VLDL receptor homolog mediating binding of lipophorin in oocyte of the mosquito Aedes aegypti
Molecular characterization of the VLDL receptor homolog mediating binding of lipophorin in oocyte of the mosquito Aedes aegypti
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DOI：
10.1016/s0965-1748(01)00068-6
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发表时间：
2001-06-22
影响因子：
3.8
通讯作者：
Raikhel, AS
中科院分区：
文献类型：
--
作者：
Cheon, HM;Seo, SJ;Raikhel, AS
载脂蛋白（Lp）在埃及伊蚊（Aedes aegypti）中作为卵黄蛋白前体起作用，并且其经由受体介导的内吞作用内化（Insect Biochem.Mel.生物学：30（2000）1161）。我们克隆和分子特征的一个假定的蚊子卵巢脂转运蛋白受体（AaLpRov）的cDNA。该cDNA全长3468 bp，编码1156个氨基酸残基，预测分子量为128.9 kDa。推导的氨基酸序列的cDNA显示，它编码的蛋白质同源物的LDL受体超家族，并且，它在N-末端像脊椎动物VLDL受体harbored八个富含半胱氨酸的配体结合重复。这种蚊子卵巢受体的推导的氨基酸序列与蝗虫载脂蛋白受体（LmLpR）的氨基酸序列最相似（64.3%），并且仅与蚊子卵黄蛋白原受体（VgR）（18.3%），另一种具有不同配体的卵巢LDLR同源物有较远的关系。AaLpRov cDNA在TnT（R）偶联网织红细胞裂解物系统中表达，共免疫沉淀实验证实受体蛋白特异性结合Lp。发育表达谱清楚地表明，AaLpRov转录本存在于卵黄发生卵巢中，在血餐后24 - 36 h达到峰值表达。原位杂交表明，AaLpRov转录本只存在于女性生殖系细胞。基于距离的系统发育分析表明，昆虫LpR和脊椎动物LDL/VLDL受体谱系分离后，从昆虫VgR谱系分歧。(C)2001爱思唯尔科技有限公司版权所有。
Lipophorin (Lp) functions as a yolk protein precursor in the mosquito Aedes aegypti and it is internalized via receptor-mediated endocytosis (Insect Biochem. Mel. Biol., 30 (2000) 1161). We cloned and molecularly characterized a putative mosquito ovarian lipophorin receptor (AaLpRov) cDNA. The cDNA has a length of 3468 bp coding for a 1156-residue protein with a predicted molecular mass of 128.9 kDa. The deduced amino acid sequence of the cDNA revealed that it encodes a protein homolog of the LDL receptor superfamily, and that it harbors eight cysteine-rich ligand binding repeats at the N-terminus like vertebrate VLDL receptors. The deduced amino acid sequence of this mosquito ovarian receptor is most similar to that of the locust lipophorin receptor (LmLpR) (64.3%), and is only distantly related to the mosquito vitellogenin receptor (VgR) (18.3%), another ovarian LDLR homolog with a different ligand. The AaLpRov cDNA was expressed in a TnT(R) Coupled Reticulocyte Lysate system, and coimmunoprecipitation experiments confirmed that the receptor protein specifically binds Lp. Developmental expression profiles clearly showed that AaLpRov transcripts are present in the vitellogenic ovary, with peak expression at 24-36 h post blood meal. In situ hybridization indicated that AaLpRov transcripts are present only in female germ line cells. Distance-based phylogenetic analyses suggest that the insect LpR and vertebrate LDL/VLDL receptor lineages separated after divergence from the insect VgR lineage. (C) 2001 Elsevier Science Ltd. All rights reserved.