Fukuta M, Matsuno K, Hui C C, Nagata T, Takiya S, Xu P X, Ueno K, Suzuki Y
National Institute for Basic Biology, Okazaki, Japan.
J Biol Chem. 1993 Sep 15;268(26):19471-5.
The POU domain is a highly conserved region found in a number of transcription factors and products of developmental control genes. We report here the isolation and characterization of a POU domain-containing cDNA (POU-M1) from the middle silk gland of Bombyx mori. It encodes a protein with a POU domain identical to that of the Drosophila Cf1-a protein. By mobility shift and nuclease protection assays, the POU-M1 protein and the putative silk gland factor 3 (SGF-3) were found to interact in an indistinguishable manner with the SC region (positions -204 to -183) of the sericin-1 gene, a key cis-acting element involved in the regulation of the gene through the interaction with SGF-3. Antibodies raised against the synthetic oligopeptide corresponding to the COOH-terminal region of the putative POU-M1 sequence reacted specifically to both the POU-M1 protein and SGF-3. Northern blot hybridization and Western blotting revealed that POU-M1 expression is regulated both temporally and spatially during silk gland development. We conclude that the POU-M1 protein is SGF-3 and propose that the differential expression of the POU-M1 gene is probably involved in the transcriptional regulation of the silk protein genes.
POU结构域是在许多转录因子和发育控制基因的产物中发现的高度保守区域。我们在此报告从家蚕中部丝腺中分离和鉴定出一个含POU结构域的cDNA（POU-M1）。它编码一种蛋白质，其POU结构域与果蝇Cf1-a蛋白的POU结构域相同。通过迁移率变动分析和核酸酶保护分析，发现POU-M1蛋白和假定的丝腺因子3（SGF-3）以难以区分的方式与丝胶蛋白-1基因的SC区域（位置-204至-183）相互作用，SC区域是一个关键的顺式作用元件，通过与SGF-3相互作用参与该基因的调控。针对与假定的POU-M1序列的COOH末端区域相对应的合成寡肽产生的抗体与POU-M1蛋白和SGF-3都发生特异性反应。Northern印迹杂交和Western印迹显示，POU-M1的表达在丝腺发育过程中受到时间和空间的调控。我们得出结论，POU-M1蛋白就是SGF-3，并提出POU-M1基因的差异表达可能参与丝蛋白基因的转录调控。
