Identification of human T-cell lymphotropic virus type I 21-base-pair repeat-specific and glial cell-specific DNA-protein complexes.
Identification of human T-cell lymphotropic virus type I 21-base-pair repeat-specific and glial cell-specific DNA-protein complexes.
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人 T 细胞嗜淋巴细胞病毒 I 型 21 碱基对重复序列特异性和神经胶质细胞特异性 DNA 蛋白复合物的鉴定。
DOI：
10.1128/jvi.68.7.4597-4608.1994
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发表时间：
1994
影响因子：
5.4
通讯作者：
Wigdahl,B
中科院分区：
文献类型：
--
作者：
Tillmann,M;Wessner,R;Wigdahl,B
人T细胞嗜淋巴细胞病毒I型（HTLV-I）编码的蛋白Tax能够通过与HTLV-I长末端重复序列（LTR）中的特定序列相互作用而反式激活HTLV-I转录，所述LTR包含含有21-bp序列的三个不完全串联重复序列的诱导型增强子。没有证据表明纯化的Tax可以在没有细胞因子的情况下与DNA结合，这表明Tax很可能通过与细胞因子的相互作用来调节转录。由于HTLV-I是成人T细胞白血病和热带痉挛性下肢轻瘫、免疫系统和神经系统疾病的记录剂，因此与21-bp重复元件相互作用的淋巴和神经胶质细胞来源的细胞因子的表征对于理解免疫和神经系统来源的细胞中涉及基础和Tax介导的转录的机制是必不可少的。利用电泳迁移率变动（EMS）分析，我们已经检测到21 bp的重复特异性和神经胶质细胞特异性的DNA-蛋白质复合物。几个21 bp的重复特异性DNA-蛋白质复合物被检测到时，核提取物来源于淋巴细胞（Jurkat，SupT 1，和H9），神经元（IMR-32和SK-N-MC），和神经胶质细胞（U-373 MG，Hs 683，和U-118）的起源与每一个反应的三个21 bp的重复元件。此外，当来自U-373 MG，Hs 683和U-118胶质细胞系的核提取物与启动子远端和中央21-bp重复元件反应时，检测到胶质细胞特异性DNA-蛋白质复合物。此外，用来自淋巴细胞和神经胶质细胞来源的核提取物和包含三个21-bp重复元件（命名为Tax应答元件1和2，TRE-1/-2）的HTLV-1长末端重复的223-bp片段进行的EMS分析也导致检测到神经胶质细胞类型特异性DNA-蛋白质复合物。与含有转录因子结合位点序列的寡核苷酸的竞争EMS分析表明，参与形成的DNA-蛋白质复合物，形成与所有三个21-bp的重复元件和神经胶质细胞特异性的DNA-蛋白质复合物的环AMP反应元件结合蛋白，以及参与的Sp1或Sp1相关因子的21-bp的重复III特异性的DNA-蛋白质复合物的形成。
The human T-cell lymphotropic virus type I (HTLV-I)-encoded protein, Tax, is capable of trans-activating HTLV-I transcription by interacting with specific sequences in the HTLV-I long terminal repeat (LTR) which comprise an inducible enhancer containing three imperfect tandem repeats of a 21-bp sequence. There is no evidence that purified Tax can bind to DNA in the absence of cellular factors, suggesting that Tax most likely regulates transcription via interaction with cellular factors. Since HTLV-I is a documented agent of adult T-cell leukemia and tropical spastic paraparesis, disorders of the immune and nervous systems, respectively, characterization of cellular factors of lymphoid and neuroglial origin which interact with the 21-bp repeat elements is essential to understanding of the mechanisms involved in basal and Tax-mediated transcription in cells of immune and nervous system origin. Utilizing electrophoretic mobility shift (EMS) analyses, we have detected both 21-bp repeat-specific and glial cell-specific DNA-protein complexes. Several 21-bp repeat-specific DNA-protein complexes were detected when nuclear extracts derived from cells of lymphoid (Jurkat, SupT1, and H9), neuronal (IMR-32 and SK-N-MC), and glial (U-373 MG, Hs683, and U-118) origin were used in reactions with each of the three 21-bp repeat elements. In addition, a glial cell-specific DNA-protein complex was detected when nuclear extracts derived from U-373 MG, Hs683, and U-118 glial cell lines reacted with the promoter-distal and central 21-bp repeat elements. Furthermore, EMS analyses performed with nuclear extracts derived from lymphocytic and glial cell origin and a 223-bp fragment of the HTLV-I long terminal repeat encompassing the three 21-bp repeat elements (designated Tax-responsive elements 1 and 2, TRE-1/-2) have also resulted in the detection of glial cell type-specific DNA-protein complexes. Competition EMS analyses with oligonucleotides containing transcription factor binding site sequences indicate the involvement of a cyclic AMP response element binding protein in the formation of DNA-protein complexes which form with all three 21-bp repeat elements and the glial cell-specific DNA-protein complex as well as the involvement of Sp1 or an Sp1-related factor in the formation of the 21-bp repeat III-specific DNA-protein complexes.