Möritz A, Grzeschik K H, Wingender E, Fink E
Department of Clinical Chemistry and Clinical Biochemistry, University of Munich, Germany.
Gene. 1993 Jan 30;123(2):277-81. doi: 10.1016/0378-1119(93)90138-s.
A complete cDNA encoding the acrosin-trypsin inhibitor, HUSI-II, was used as a probe to isolate genomic clones from a human placenta library. Three clones which cover the entire HUSI-II gene were isolated and characterized. The exon-intron organization of the gene was determined and found to be identical to other known Kazal-type inhibitor-encoding genes. The striking similarity in the amino acid sequences which was found previously in HUSI-II and glycoprotein hormone beta-subunits, is neither reflected in codon usage nor in the exon-intron arrangement of the genes. A 1.8-kb segment 5' of the gene was sequenced. The analysis of this sequence showed that HUSI-II contains a G + C-rich region upstream from the transcription start point (tsp) which fulfills the criteria for a CpG island. Furthermore, in the first intron, a potential glucocorticoid-responsive element was found as a half-palindrome flanked by two CACCC elements. Determination of the tsp by S1 mapping revealed that HUSI-II has multiple tsp. Genomic Southern hybridization was used to show that HUSI-II is a single-copy gene. The localization of the gene to chromosome 4 was determined by hybridization of a 5' genomic fragment to the DNA of a panel of somatic hybrids between human and rodent cells.
一个编码顶体蛋白酶 - 胰蛋白酶抑制剂HUSI-II的完整cDNA被用作探针，从人胎盘文库中分离基因组克隆。分离并鉴定了三个覆盖整个HUSI-II基因的克隆。确定了该基因的外显子 - 内含子组织，发现其与其他已知的编码Kazal型抑制剂的基因相同。先前在HUSI-II和糖蛋白激素β亚基中发现的氨基酸序列的显著相似性，在密码子使用或基因的外显子 - 内含子排列中均未体现。对该基因5'端1.8kb的片段进行了测序。该序列分析表明，HUSI-II在转录起始点（tsp）上游含有一个富含G + C的区域，该区域符合CpG岛的标准。此外，在第一个内含子中，发现了一个潜在的糖皮质激素反应元件，其为一个半回文结构，两侧有两个CACCC元件。通过S1作图确定tsp，结果显示HUSI-II有多个tsp。基因组Southern杂交表明HUSI-II是一个单拷贝基因。通过将一个5'基因组片段与人 - 啮齿动物细胞间的一组体细胞杂种的DNA杂交，确定了该基因在4号染色体上的定位。
