CLONING AND EXPRESSION OF THE GENE OF HEMOCYTIN, AN INSECT HUMORAL LECTIN WHICH IS HOMOLOGOUS WITH THE MAMMALIAN VON-WILLEBRAND-FACTOR
CLONING AND EXPRESSION OF THE GENE OF HEMOCYTIN, AN INSECT HUMORAL LECTIN WHICH IS HOMOLOGOUS WITH THE MAMMALIAN VON-WILLEBRAND-FACTOR
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DOI：
10.1016/0167-4781(94)00202-e
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发表时间：
1995-02-21
期刊：
影响因子：
--
通讯作者：
MORI, H
中科院分区：
文献类型：
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作者：
KOTANI, E;YAMAKAWA, M;MORI, H
无脊椎动物凝集素在非特异性自卫机制中起重要作用，因为无脊椎动物不合成特异性抗体。我们报告的几个重叠的cDNA编码的整个蚕（家蚕）凝集素，我们建议称之为血细胞素的克隆。该序列全长10477 bp，编码3133个氨基酸。在血细胞素C端序列中发现了C型动物凝集素糖识别结构域的特征。当将编码该区域的cDNA导入杆状病毒载体时，在重组病毒感染的细胞的培养液中检测到血凝活性。这些活性被D-甘露糖、N-乙酰-D-半乳糖胺和D-麦芽糖抑制，它们是真实血细胞素的半抗原结合物。斑点杂交和北方杂交分析表明，血细胞素基因在蚕蛹变态期和/或注射大肠杆菌和脂多糖后的血细胞中有转录。家蚕幼虫注射血细胞素C端后，血淋巴中出现血细胞聚集现象。血细胞素与哺乳动物血管性血友病因子具有显著的同源性，后者参与血小板粘附于内皮下。此外，血细胞素具有与凝血因子V和VIII同源的区域。这些结果表明，血细胞素分子是一种粘附蛋白，与止血或包裹异物进行自卫有关。
Invertebrate lectins play an important role in a non-specific self-defense mechanism, as invertebrates do not synthesize specific antibodies. We report the cloning of several overlapping cDNAs encoding the entire silkworm (Bombyx mori) lectin, which we propose to call hemocytin. The sequence (10477 bp) encoded 3133 amino acids. The characteristic features of the carbohydrate-recognition domain of C-type animal lectin were revealed at C-terminal sequence of hemocytin. When cDNA encoding this region was introduced into baculovirus vector, hemagglutinating activities were detected in the culture fluid of a recombinant virus-infected cells. These activities were inhibited by D-mannose, N-acetyl-D-galactosamine, and D-maltose which are haptenic saccharides of authentic hemocytin. Analysis of dot and Northern blot hybridization revealed that hemocytin gene was transcribed in hemocytes of the silkworm at larval-pupal metamorphosis and/or after the injection of Escherichia coli and lipopolysaccharide. After silkworm larvae were injected with C-terminal portion of hemocytin, aggregation of hemocytes was observed in the hemolymph. Hemocytin has significant homology with mammalian von Willebrand factor which involves in platelet adhesion to subendothelium. Also, hemocytin has a homologous region with coagulation factor V and VIII. These results suggest that hemocytin molecule is an adhesive protein and relates to hemostasis or encapsulation of foreign substances for self-defense.