Liu Yan, Yu Lian, Guo Xiuyang, Guo Tingqing, Wang Shengpeng, Lu Changde
College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou 310027, China.
Biochem Biophys Res Commun. 2006 Mar 31;342(1):273-9. doi: 10.1016/j.bbrc.2006.01.140. Epub 2006 Feb 6.
The gene encoding sericin 1 (Ser1) of silkworm (Bombyx mori) is specifically expressed in the middle silk gland cells. To identify element involved in this transcription-dependent spatial restriction, truncation of the 5' terminal from the sericin 1 (Ser1) promoter is studied in vivo. A 209bp DNA sequence upstream of the transcriptional start site (-586 to -378) is found to be responsible for promoting tissue-specific transcription. Analysis of this 209bp region by overlapping deletion studies showed that a 25bp region (-500 to -476) suppresses the ectopic expression of the Ser1 promoter. An unknown factor abundant in fat body nuclear extracts is shown to bind to this 25bp fragment. These results suggest that this 25bp region and the unknown factor are necessary for determining the tissue-specificity of the Ser1 promoter.
家蚕编码丝胶蛋白1（Ser1）的基因在中部丝腺细胞中特异性表达。为了鉴定参与这种转录依赖性空间限制的元件，在体内研究了丝胶蛋白1（Ser1）启动子5'末端的截短。发现转录起始位点上游209bp的DNA序列（-586至-378）负责促进组织特异性转录。通过重叠缺失研究对该209bp区域进行分析表明，一个25bp区域（-500至-476）抑制Ser1启动子的异位表达。脂肪体核提取物中丰富的一种未知因子被证明可与该25bp片段结合。这些结果表明，该25bp区域和未知因子对于确定Ser1启动子的组织特异性是必需的。
