Characterization of TcHMGB, a high mobility group B family member protein from Trypanosoma cruzi
Characterization of TcHMGB, a high mobility group B family member protein from Trypanosoma cruzi
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DOI：
10.1016/j.ijpara.2011.06.009
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发表时间：
2011-09-01
影响因子：
4
通讯作者：
Serra, Esteban
中科院分区：
文献类型：
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作者：
Cribb, Pamela;Perozzi, Marina;Serra, Esteban
高迁移率B组蛋白（HMGB）是一种丰富的非组蛋白染色质蛋白，在许多核功能的执行和控制中起重要作用。基于同源性检索，我们确定了来自锥虫的HMGB家族成员TcHMGB蛋白的编码序列，TcHMGB具有两个HMG盒结构域，类似于哺乳动物的HMGB，但缺乏典型的c端酸性尾。相反，它含有一个110个氨基酸的长n端结构域。TcHMGB n端结构域在TriTryp序列之间保守（70-80%相似），似乎是着丝质体hmgb的特征。尽管存在这些差异，但TcHMGB保持了HMG盒结构功能：我们在凝胶移位试验中证明了锥虫HMGB结合扭曲的DNA结构，如十字形DNA。与其他HMGB家族成员类似，TcHMGB也能够弯曲T4连接酶环化试验确定的线性DNA。免疫荧光和western blot检测显示，TcHMGB是一个在所有生命周期阶段都表达的核蛋白。然而，蛋白质水平似乎在整个生命周期中变化，这可能与先前描述的异染色质分布和转录率的变化有关。(C) 2011澳大利亚寄生虫学学会Elsevier Ltd.出版。版权所有。
High mobility group B (HMGB) proteins are highly abundant non-histone chromatin proteins that play important roles in the execution and control of many nuclear functions. Based on homology searches, we identified the coding sequence for the TcHMGB protein, an HMGB family member from Trypanosoma TcHMGB has two HMG box domains, similar to mammalian HMGBs, but lacks the typical C-terminal acidic tail. Instead, it contains a 110 amino acid long N-terminal domain. The TcHMGB N-terminal domain is conserved between the TriTryp sequences (70-80% similarity) and seems to be characteristic of kinetoplastid HMGBs. Despite these differences, TcHMGB maintains HMG box architectural functions: we demonstrated that the trypanosomatid HMGB binds distorted DNA structures such as cruciform DNA in gel shift assays. TcHMGB is also able to bend linear DNA as determined by T4 ligase circularization assays, similar to other HMGB family members. Immunofluorescence and western blot assays showed that TcHMGB is a nuclear protein expressed in all life cycle stages. Protein levels, however, seem to vary throughout the life cycle, which may be related to previously described changes in heterochromatin distribution and transcription rates. (C) 2011 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.