THE B-CELL-SPECIFIC OCT-2 PROTEIN CONTAINS POU BOX-TYPE AND HOMEO BOX-TYPE DOMAINS
THE B-CELL-SPECIFIC OCT-2 PROTEIN CONTAINS POU BOX-TYPE AND HOMEO BOX-TYPE DOMAINS
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DOI：
10.1101/gad.2.12a.1570
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发表时间：
1988-12-01
影响因子：
10.5
通讯作者：
SHARP, PA
中科院分区：
文献类型：
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作者：
CLERC, RG;CORCORAN, LM;SHARP, PA
免疫球蛋白基因启动子的转录由八核苷酸序列元件控制。已确定编码B细胞特异性蛋白Oct-2的cDNA的序列。该蛋白特异性识别八核苷酸元件，并且是先前鉴定的NF-A2蛋白家族的一部分。Oct-2的DNA结合结构域在结构上与同源盒共有序列相关，因此包含潜在的螺旋-转角-螺旋序列。Oct-2还具有一个潜在的“亮氨酸拉链”结构域，其中四个lecucine每个正好由七个残基组成。Oct-2与蛋白质Oct-1的比较，Oct-1也识别八核苷酸元件，但在所有细胞类型中组成型表达，通过60个残基的DNA结合结构域，以及75个残基的相邻道显示出高序列保守性。后一个保守区域也在垂体细胞和线虫中表达的调控基因中发现，并被称为POU盒。由于分离到两种不同的cDNA，因此提出oct-2基因以剪接模式不同的多个mRNA表达。最有趣的是，oct-2 cDNA包含第二个重叠的开放阅读框架，长度为278个残基，这也可能是B细胞发育的重要蛋白质。
Transcription of promoters of immunoglobulin genes is controlled by an octanucleotide sequence element. The sequence of a cDNA encoding a B-cell-specific protein, Oct-2, has been determined. This protein specifically recognizes the octanucleotide element and is part of the previously identified NF-A2 family of proteins. The DNA-binding domain of Oct-2 is structurally related to the homeo box consensus and thus contains a potential helix-turn-helix sequence. Oct-2 also possesses a potential ''leucine zipper'' domain, where four lecucines are each spearated by exactly seven residues. Comparisons of Oct-2 with protein Oct-1, which also recognizes the octanucleotide element but is constitutively expressed in all cell types, show high sequence conservation through the 60-residue DNA-binding domain, as well as an adjacent tract of 75 residues. The latter conserved region is also found in regulatory genes expressed in pituitary cells and nematodes and has been termed a POU box. Because two different cDNAs were isolated, it is proposed that the oct-2 gene is expressed as multiple mRNAs that very in splicing patterns. Most interestingly, the oct-2 cDNA contains a second overlapping open reading frame, 278 residues in length, which might also specify a protein important for B-cell development.