Drosophila melanogaster transferrin. Cloning, deduced protein sequence, expression during the life cycle, gene localization and up-regulation on bacterial infection.
Drosophila melanogaster transferrin. Cloning, deduced protein sequence, expression during the life cycle, gene localization and up-regulation on bacterial infection.
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DOI：
10.1046/j.1432-1327.1999.00173.x
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发表时间：
2001-12
期刊：
影响因子：
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通讯作者：
Toyoshi Yoshiga;Teodora Georgieva;B. Dunkov;Nedjalka Harizanova;K. Ralchev;John H. Law
中科院分区：
文献类型：
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作者：
Toyoshi Yoshiga;Teodora Georgieva;B. Dunkov;Nedjalka Harizanova;K. Ralchev;John H. Law
使用由其他双翅目转铁蛋白序列设计的两个引物扩增的 PCR 片段，从卵巢 cDNA 文库中克隆果蝇转铁蛋白 cDNA。该克隆（2035 bp）编码 641 个氨基酸的蛋白质，其中含有 29 个氨基酸的信号肽。与其他昆虫转铁蛋白一样，果蝇转铁蛋白似乎仅在 N 末端叶中具有功能性铁结合位点。 C 端叶缺乏其他转铁蛋白中发现的铁结合残基，并且具有大量缺失，这使其比其他转铁蛋白中的功能性 C 端叶小得多。使用地高辛标记的转铁蛋白 cDNA 探针进行原位杂交显示该基因位于 X 染色体上的位置 17B1-2。 Northern印迹分析表明，转铁蛋白mRNA存在于幼虫、蛹和成虫阶段，但在胚胎中检测不到。饮食中补充铁会导致转铁蛋白 mRNA 水平降低。当成年果蝇接种细菌（大肠杆菌）时，转铁蛋白 mRNA 合成相对于对照显着增加。
Drosophila melanogaster transferrin cDNA was cloned from an ovarian cDNA library by using a PCR fragment amplified by two primers designed from other dipteran transferrin sequences. The clone (2035 bp) encodes a protein of 641 amino acids containing a signal peptide of 29 amino acids. Like other insect transferrins, Drosophila transferrin appears to have a functional iron-binding site only in the N-terminal lobe. The C-terminal lobe lacks iron-binding residues found in other transferrins, and has large deletions which make it much smaller than functional C-terminal lobes in other transferrins. In-situ hybridization using a digoxigenin labeled transferrin cDNA probe revealed that the gene is located at position 17B1-2 on the X chromosome. Northern blot analysis showed that transferrin mRNA was present in the larval, pupal and adult stages, but was not detectable in the embryo. Iron supplementation of the diet resulted in lower levels of transferrin mRNA. When adult flies were inoculated with bacteria (Escherichia coli), transferrin mRNA synthesis was markedly increased relative to controls.