Joseph D R, Hall S H, Conti M, French F S
Department of Pediatrics, University of North Carolina, Chapel Hill 27599.
Mol Endocrinol. 1988 Jan;2(1):3-13. doi: 10.1210/mend-2-1-3.
A genomic clone has been characterized for androgen-binding protein (ABP), a Sertoli cell secretory protein that is regulated by androgens and FSH. A 5.3-kilobase pair Sstl DNA fragment was sequenced and found to contain the entire coding region of the gene, which is divided into 8 exons. The major transcription initiation site in the testis was localized by primer extension with two unique oligomers. In addition, a minor initiation site was identified that appears to originate from another promoter. The gene does not contain a conventional TATA box immediately upstream from the major start site; rather, the sequence TACCTA occurs at residue -24. This sequence has been described functionally as a TATA-like element in the SV40 major late gene. Other potential regulatory elements include a sequence related to the cAMP response element at residue -126 base pair. Using primary Sertoli cell cultures, it was found that (Bu)2cAMP or FSH increases ABP mRNA levels 3-5 fold, with a 2-fold increase in the level of secreted ABP. Southern blot analysis of rat genomic DNA indicated that there is a single gene for ABP in the rat. The existence of one gene supports the idea that sex hormone binding globulin produced by fetal rat liver is coded by the same gene.
已对雄激素结合蛋白（ABP）的基因组克隆进行了表征，ABP是一种由支持细胞分泌的蛋白质，受雄激素和促卵泡激素调节。对一个5.3千碱基对的Sstl DNA片段进行了测序，发现其包含该基因的完整编码区，该编码区分为8个外显子。通过用两种独特的寡聚物进行引物延伸，确定了睾丸中的主要转录起始位点。此外，还鉴定出一个次要起始位点，它似乎源自另一个启动子。该基因在主要起始位点上游紧邻处不包含常规的TATA盒；相反，序列TACCTA出现在-24位残基处。该序列在功能上被描述为SV40主要晚期基因中的类TATA元件。其他潜在的调控元件包括在-126碱基对处与cAMP反应元件相关的序列。使用原代支持细胞培养物发现，（Bu）2cAMP或促卵泡激素可使ABP mRNA水平提高3至5倍，分泌的ABP水平提高2倍。对大鼠基因组DNA的Southern印迹分析表明，大鼠中ABP只有一个基因。一个基因的存在支持了这样一种观点，即胎鼠肝脏产生的性激素结合球蛋白由同一基因编码。
