Coordinate regulation of HLA class II genes: a novel DNA binding complex.
Coordinate regulation of HLA class II genes: a novel DNA binding complex.
复制标题
HLA II 类基因的协调调节：一种新型 DNA 结合复合物。
DOI：
10.1016/0161-5890(95)00151-4
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发表时间：
1996
影响因子：
3.6
通讯作者：
Lee,JS
中科院分区：
文献类型：
--
作者：
Bannish,G;Hume,C;Lee,JS
We have characterized a nuclear protein complex from B lymphoblastoid cell lines that binds to HLA class II promoters as detected by electrophoretic gel mobility shift assays (EMSA). This complex (Cl) binds to three independent sites in the proximal DRA promoter which have not been identified previously as cis-acting elements. Cl is very abundant in Burkitt's lymphoma cell lines, but less abundant in “normal” B lymphoblastoid cell lines. The binding specificity of the Cl complex was analysed using competition experiments and chemical footprinting methods. Complexes with specificity similar to Cl also bind the DPA and DQA promoters. Though mutation of the sequences in the DRA promoter that severely reduced binding of the Cl complex had no effect on the ability of the DRA fragment to drive transcription of the reporter gene in transient expression or in vitro transcription assays, this conservation of binding sites among all class II promoters tested suggests functional relevance in transcription. In addition, complexes similar to Cl were observed in nuclear extracts from all cell lines examined, but minor differences in mobility appeared to correlate with class II expression. Thus, the Cl complex may act as a trans-acting factor in MHC class II expression.
