Characterization of an Entamoeba histolytica high-mobility-group box protein induced during intestinal infection
Characterization of an Entamoeba histolytica high-mobility-group box protein induced during intestinal infection
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DOI：
10.1128/ec.00123-08
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发表时间：
2008-09-01
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影响因子：
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通讯作者：
Gilchrist, Carol A.
中科院分区：
文献类型：
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作者：
Abhyankar, Mayuresh M.;Hochreiter, Amelia E.;Gilchrist, Carol A.
单细胞真核生物溶组织内阿米巴是一种人类寄生虫，可引起阿米巴痢疾和肝脓肿。一个全基因组分析的基因表达调节肠道定植和入侵确定了上调的转录，编码一个假定的高迁移率族蛋白（HMGB）蛋白，EhHMGB 1。我们测试了EhHMGB 1是否编码功能性HMGB蛋白，并确定其在控制寄生虫基因表达中的作用。重组EhHMGB 1能够在体外弯曲DNA，这是HMGB蛋白的特征。通过突变分析证明，其他HMGB蛋白中DNA弯曲活性所需的核心保守残基对EhHMGB 1活性至关重要。EhHMGB 1还能够在体外增强人p53与其同源DNA序列的结合，这是HMGB 1蛋白所预期的。共聚焦显微镜，使用针对重组蛋白的抗体，证实了其核定位。HM 1：IMSS滋养体中EhHMGB 1的过表达导致了33种参与多种细胞功能的转录物的调节。其中，20个也在肠道阿米巴病小鼠模型中的第1天或第29天进行了调节。值得注意的是，四个转录与已知的毒力作用，包括两个编码半乳糖/半乳糖NAc凝集素轻链，调制响应EhHMGB 1过表达。我们的结论是，EhHMGB 1是一个真正的HMGB蛋白的能力，重演部分的寄生虫基因表达的调制过程中看到的适应宿主肠道。
The unicellular eukaryote Entamoeba histolytica is a human parasite that causes amebic dysentery and liver abscess. A genome-wide analysis of gene expression modulated by intestinal colonization and invasion identified an upregulated transcript that encoded a putative high-mobility-group box (HMGB) protein, EhHMGB1. We tested if EhHMGB1 encoded a functional HMGB protein and determined its role in control of parasite gene expression. Recombinant EhHMGB1 was able to bend DNA in vitro, a characteristic of HMGB proteins. Core conserved residues required for DNA bending activity in other HMGB proteins were demonstrated by mutational analysis to be essential for EhHMGB1 activity. EhHMGB1 was also able to enhance the binding of human p53 to its cognate DNA sequence in vitro, which is expected for an HMGB1 protein. Confocal microscopy, using antibodies against the recombinant protein, confirmed its nuclear localization. Overexpression of EhHMGB1 in HM1:IMSS trophozoites led to modulation of 33 transcripts involved in a variety of cellular functions. Of these, 20 were also modulated at either day 1 or day 29 in the mouse model of intestinal amebiasis. Notably, four transcripts with known roles in virulence, including two encoding Gal/GalNAc lectin light chains, were modulated in response to EhHMGB1 overexpression. We concluded that EhHMGB1 was a bona fide HMGB protein with the capacity to recapitulate part of the modulation of parasite gene expression seen during adaptation to the host intestine.