CLONING OF A LYMPHOID-SPECIFIC CDNA-ENCODING A PROTEIN-BINDING THE REGULATORY OCTAMER DNA MOTIF
CLONING OF A LYMPHOID-SPECIFIC CDNA-ENCODING A PROTEIN-BINDING THE REGULATORY OCTAMER DNA MOTIF
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DOI：
10.1126/science.3399892
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发表时间：
1988-07-29
期刊：
影响因子：
56.9
通讯作者：
BALTIMORE, D
中科院分区：
文献类型：
--
作者：
STAUDT, LM;CLERC, RG;BALTIMORE, D
八聚体DNA序列在指导B淋巴细胞免疫球蛋白基因的转录中起关键作用。利用放射性DNA直接结合的新技术，从BJAB细胞系中筛选了一个互补的DNA表达文库。gt11噬菌体获得分子cDNA克隆，代表假定的B淋巴细胞特异性八聚体结合蛋白。用含有四拷贝八聚体序列的DNA筛选斑块，鉴定出阳性噬菌体重组体。通过诱导一个噬菌体的溶原与一个单体八聚体探针结合而产生的融合蛋白。从噬菌体插入的cDNA与B淋巴细胞中发现的信使RNA杂交，但在大多数其他细胞中没有发现。因此，该cDNA来源于一个基因（oct-2），该基因指定在B淋巴细胞中优先表达的八聚体结合蛋白，证明至少有一个基因存在细胞特异性转录因子，其数量通过信使RNA可用性控制。
An octamer DNA sequence plays a critical role in directing transcription of immunoglobulin genes in B lymphocytes. A new technique of direct binding of radioactive DNA was used to screen a complementary DNA expression library from the BJAB cell line in .lambda.gt11 phage to derive molecular cDNA clones representing a putative B lymphocyte-specific octamer binding protein. The plaques were screened with DNA containing four copies of the octamer sequence and positive phage recombinants were identified. The fusion protein produced on inducing a lysogen of one phage bound to a monomeric octamer probe. The cDNA insert from this phage hybridized to messenger RNA found in B lymphocytes, but not in most other cells. Thus, this cDNA derives from a gene (oct-2) that specifies an octamer binding protein expressed preferentially in B lymphocytes, proving that, for at least one gene, a cell-specific transcription factor exists and its amount is controlled through messenger RNA availability.