Serpent regulates Drosophila immunity genes in the larval fat body through an essential GATA motif
Serpent regulates Drosophila immunity genes in the larval fat body through an essential GATA motif
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DOI：
10.1093/emboj/18.14.4013
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发表时间：
1999-07-15
期刊：
影响因子：
11.4
通讯作者：
Engström, Y
中科院分区：
文献类型：
--
作者：
Petersen, UM;Kadalayil, L;Engström, Y
昆虫具有强大的免疫系统，其对感染的应答导致大量产生不同的抗微生物肽。许多免疫基因的调节区包含加塔基序，其邻近于κ B基序。Rel蛋白介导的Cecropin A1的高水平表达以前已被证明需要加塔位点沿着κ B位点。我们提供的证据表明，加塔基序是Cecropin A1基因在幼虫脂肪体中表达所必需的，但在成虫脂肪体中是不存在的。核DNA结合活性与天蚕素A1加塔基序相互作用，其性质与果蝇加塔因子Serpent相同。GATA结合活性被Serpent特异性抗体识别，证明其同一性。我们发现，蛇是核幼虫的脂肪体细胞和血细胞感染前后。过表达后，Serpent以GATA依赖的方式增加天蚕素A1的转录。我们认为Serpent在免疫基因的组织特异性表达中起着关键作用，它通过诱导Rel蛋白对感染的反应来激活免疫基因。
Insects possess a powerful immune system, which in response to infection leads to a vast production of different antimicrobial peptides, The regulatory regions of many immunity genes contain a GATA motif in proximity to a kappa B motif, Upon infection, Rel proteins enter the nucleus and activate transcription of the immunity genes. High levels of Rel protein-mediated Cecropin A1 expression previously have been shown to require the GATA site along with the kappa B site, We provide evidence demonstrating that the GATA motif is needed for expression of the Cecropin A1 gene in larval fat body, but is dispensable in adult fat body. A nuclear DNA-binding activity interacts with the Cecropin A1 GATA motif with the same properties as the Drosophila GATA factor Serpent. The GATA-binding activity is recognized by Serpent-specific antibodies, demonstrating their identity. We show that Serpent is nuclear in larval fat body cells and haemocytes both before and after infection. After overexpression, Serpent increases Cecropin A1 transcription in a GATA-dependent manner. We propose that Serpent plays a key role in tissue-specific expression of immunity genes, by priming them for inducible activation by Rel proteins in response to infection.