Huang Qianli, Guo Jiaming, Ge Qq, Li-Ling Jesse, Chen Xueping, Ma Fei
Department of Chemistry, University of Science and Technology of China, Hefei 230031, China.
Genetica. 2009 May;136(1):127-34. doi: 10.1007/s10709-008-9323-1. Epub 2008 Sep 25.
To further elucidate the characteristics and potential functions of non-coding region of certain genes, we here systematically examined alternative promoter regions and repeated elements in non-coding regulatory regions of human tissue-specific genes. The results demonstrated that the different types of tissue-specific gene show distinct characteristics, such as the type of alternative promoters, CpG islands, initiating intervallic dinucleotides, and repeat elements. Surprisingly, 74.8% of selected genes contain more than one putative alternative promoter (PAP), and about 92.11% of signal receptors (membrane-bound) possess PAPs. Moreover, a specific PAP type (GC-GC type: both the downstream (+300) and the upstream (-700) regions of transcription start sites are GC-rich) is dominant in human tissue-specific genes and the tissue-specific transcription factors have significantly higher proportion of GC-GC type PAPs. Notably, our data indicated that more than 80% of PAPs are CpG-poor in the considered genes. Furthermore, our findings revealed an inverse tendency between transposable elements and other repeated elements in the 5' flanking regions. These results seem to imply that the distinct alternative promoters and repeated elements may contribute to the regulation and divergence of human tissue-specific genes.
为了进一步阐明某些基因非编码区的特征和潜在功能，我们在此系统地研究了人类组织特异性基因非编码调控区中的可变启动子区域和重复元件。结果表明，不同类型的组织特异性基因表现出不同的特征，如可变启动子的类型、CpG岛、起始间隔双核苷酸和重复元件。令人惊讶的是，74.8%的选定基因含有不止一个假定的可变启动子（PAP），约92.11%的信号受体（膜结合型）拥有PAP。此外，一种特定的PAP类型（GC-GC型：转录起始位点的下游（+300）和上游（-700）区域均富含GC）在人类组织特异性基因中占主导地位，且组织特异性转录因子中GC-GC型PAP的比例显著更高。值得注意的是，我们的数据表明，在所研究的基因中，超过80%的PAP缺乏CpG。此外，我们的研究结果揭示了5'侧翼区域中转座元件与其他重复元件之间的相反趋势。这些结果似乎意味着不同的可变启动子和重复元件可能有助于人类组织特异性基因的调控和分化。
