Kulesh D A, Oshima R G
Cancer Research Center, La Jolla Cancer Research Foundation, California 92037.
Genomics. 1989 Apr;4(3):339-47. doi: 10.1016/0888-7543(89)90340-6.
The complete sequence of the human keratin 18 (K18) gene was determined. The K18 gene is 3791 bp in length and the K18 protein is coded for by seven exons. The exon structure of K18 has been conserved compared to that of other keratin genes, with the exception of a single 3' terminal exon that codes for the tail domain of the protein that is represented by two exons in epidermal keratins. The K18 gene contains an unusual AG/GC donor splice site of intron 3 instead of the consensus AG/GT sequence. This variation is not seen in any other intermediate filament genes. The promoter region of the gene contains a TATA box, six potential SP1 binding sites, and 10 copies of CACCC boxes but lacks any CCAAT boxes and is surprisingly different from the immediately 5' flanking region of the homologous mouse Endo B gene. However, both genes contain small CpG islands surrounding the 5' end of exon 1 and, in addition, conserve repetitive Alu potential transcription units approximately 300 nt upstream of the transcriptional start site.
已确定人类角蛋白18（K18）基因的完整序列。K18基因长度为3791 bp，K18蛋白由七个外显子编码。与其他角蛋白基因相比，K18的外显子结构具有保守性，但有一个单一的3'末端外显子除外，该外显子编码蛋白的尾部结构域，而在表皮角蛋白中该结构域由两个外显子代表。K18基因在第3内含子处含有一个不寻常的AG/GC供体剪接位点，而非共有序列AG/GT。这种变异在任何其他中间丝基因中均未出现。该基因的启动子区域包含一个TATA盒、六个潜在的SP1结合位点和10个CACCC盒，但缺乏任何CCAAT盒，且与同源小鼠Endo B基因紧邻的5'侧翼区域惊人地不同。然而，两个基因在第1外显子5'端周围均含有小的CpG岛，此外，在转录起始位点上游约300 nt处保留了重复的Alu潜在转录单元。
