Stress and transcriptional regulation of tick ferritin HC.
Stress and transcriptional regulation of tick ferritin HC.
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蜱铁蛋白 HC 的应激和转录调控。
DOI：
10.1111/j.0962-1075.2004.00502.x
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Azad,AF
中科院分区：
文献类型：
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作者：
Mulenga,A;Simser,JA;Macaluso,KR;Azad,AF
我们先前鉴定了编码铁蛋白HC（HC）亚基同源物（DVFER）的部分可变革蜱cDNA，其在被蒙大拿立克次体感染的蜱中差异性上调（Mulengaet al.，2003年a）。我们已经使用cDNA末端的快速扩增来克隆全长DVFER cDNA及其来自木蜱安氏圆蜱（D. andersoni，DAFER）的表观直系同源物，两者都显示出与脊椎动物而不是昆虫铁蛋白的高度序列相似性。DVFER和DAFER在5′非翻译区（核苷酸位置，16-42）都含有推定的铁反应元件的茎环结构和脊椎动物铁蛋白HC亚基典型的铁氧化酶中心环。来自未进食和部分进食的完整蜱以及解剖的蜱组织的蛋白质和RNA的定量Western和北方印迹分析证明DVFER是组成性和普遍表达的。基于检测到的蛋白质和mRNA条带的光密度分析，DVFER主要在中肠中表达，并且在较小程度上在唾液腺、卵巢和脂肪体中表达。假处理（机械损伤）和变异革兰氏阴性杆菌的大肠杆菌激发刺激DVFER mRNA丰度随时间点统计学显著增加（分别为1.5倍和1.30倍），与未处理对照蜱匹配。这些数据表明，DVFER mRNA的非特异性上调响应机械损伤或细菌感染诱导的压力。
We previously identified a partialDermacentor variabiliscDNA encoding ferritin HC (HC) subunit homolog (DVFER) that was differentially upregulated inRickettsia montanensisinfected ticks (Mulengaet al., 2003a). We have used rapid amplification of cDNA ends to clone full‐length DVFER cDNA and its apparent ortholog from the wood tick,D. andersoni(DAFER), both of which show high sequence similarity to vertebrate than insect ferritin. Both DVFER and DAFER contain the stem–loop structure of a putative iron responsive element in the 5′ untranslated region (nucleotide positions, 16–42) and the feroxidase centre loop typical for vertebrate ferritin HC subunits. Quantitative Western and Northern blotting analyses of protein and RNA from unfed and partially fed whole tick as well as dissected tick tissues demonstrated that DVFER is constitutively and ubiquitously expressed. Based on densitometric analysis of detected protein and mRNA bands, DVFER is predominantly expressed in the midgut, and to a lesser extent in the salivary glands, ovary and fatbody. Sham treatment (mechanical injury) andEscherichia colichallenge ofD. variabilisticks stimulated statistically significant (≈ 1.5‐ and ≈ 3.0‐fold, respectively) increases in DVFER mRNA abundance over time point matched naive control ticks. These data suggest that DVFER mRNA is nonspecifically up regulated in response to mechanical injury or bacterial infection induced stress.