BACTERIA-INDUCED PROTEIN-P4 (HEMOLIN) FROM MANDUCA-SEXTA - A MEMBER OF THE IMMUNOGLOBULIN SUPERFAMILY WHICH CAN INHIBIT HEMOCYTE AGGREGATION
BACTERIA-INDUCED PROTEIN-P4 (HEMOLIN) FROM MANDUCA-SEXTA - A MEMBER OF THE IMMUNOGLOBULIN SUPERFAMILY WHICH CAN INHIBIT HEMOCYTE AGGREGATION
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DOI：
10.1002/arch.940180410
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发表时间：
1991-01-01
影响因子：
2.2
通讯作者：
KANOST, MR
中科院分区：
文献类型：
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作者：
LADENDORFF, NE;KANOST, MR
昆虫对细菌感染的反应是诱导大量血淋巴蛋白质的合成。天蛾幼虫的主要诱导血淋巴蛋白是一种M（r）= 48，000的糖蛋白，称为P4。我们已经从脂肪体cDNA文库中分离出了P4的克隆，该文库是从注射细菌的幼虫中分离的RNA构建的。该cDNA具有一个开放阅读框，编码一个411个残基的多肽，其具有疏水性的NH 2-末端序列，这似乎是一个信号肽。推导的氨基酸序列分析表明，P4是免疫球蛋白（IG）基因超家族的成员，主要由四个C2型IG结构域组成。分枝Sexta P4氨基酸序列与透明霉（Hyalophora cecropia）的血红素蛋白（P4）有60%的同源性。“hemolin”这个名字也被M. Sexta P4蛋白。5龄幼虫注射细菌后1 h内和成虫注射细菌后4 h内脂肪体中Hemolin mRNA水平开始增加。Hemolin与血细胞表面结合并抑制血细胞聚集反应，表明该蛋白在昆虫对细菌感染的识别和反应过程中调节血细胞粘附的作用。
The synthesis of a number of hemolymph proteins is induced in insects in response to bacterial infections. The major induced hemolymph protein in larvae of Manduca sexta is a glycoprotein of M(r) = 48,000 known as P4. We have isolated a clone for P4 from a fat body cDNA library constructed from RNA isolated from larvae injected with bacteria. The cDNA has an open reading frame encoding a 411 residue polypeptide with a hydrophobic NH2-terminal sequence, which appears to be a signal peptide. Analysis of the deduced amino acid sequence shows that P4 is a member of the immunoglobulin (Ig) gene superfamily, and is composed largely of four C2 type Ig domains. The M. sexta P4 amino acid sequence is 60% identical with hemolin (P4) from Hyalophora cecropia. The name "hemolin" has also been adopted for the M. sexta P4 protein. Hemolin mRNA levels in fat body begin to increase within 1 h after injection of bacteria into fifth instar larvae and within 4 h after injection of adults. Hemolin associates with the surface of hemocytes and inhibits hemocyte aggregation responses, suggesting a role for the protein in modulating hemocyte adhesion during recognition and response to bacterial infections in insects.