Yang Z, Sugawara M, Ponath P D, Wessendorf L, Banerji J, Li Y, Strominger J L
Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, MA 02138.
Proc Natl Acad Sci U S A. 1990 Dec;87(23):9226-30. doi: 10.1073/pnas.87.23.9226.
The interferon gamma (IFN-gamma) response region of the human class II major histocompatibility complex gene, DPA, has been localized to a 52-base-pair (bp) DNA fragment in the proximal promotor at -107 to -55 bp after transfection into HeLa cells of a series of 5', 3', and gap deletion mutants linked to a reporter gene, human growth hormone, as well as of synthetic oligonucleotides fused to the heterologous promoter thymidine kinase. The 52-mer sequence contains the X and Y box elements conserved in all class II genes; their presence is indispensable for IFN-gamma inducibility. Furthermore, an additional 5 bp immediately 5' of the X box of the DPA gene are necessary and sufficient for IFN-gamma induction. This region may contain an IFN-gamma response element. A closely related sequence has also been found in the vicinity of the critical deletion sites of three other well-studied class II gene promoters, all of which require a much longer sequence 5' of the X box. A fourth element, the W element, located about 15 bp 5' of the X box in all class II genes, is clearly of little importance in IFN-gamma inducibility of the DPA gene.
人类Ⅱ类主要组织相容性复合体基因DPA的干扰素γ（IFN-γ）反应区域，在与报告基因人类生长激素相连的一系列5'、3'和缺口缺失突变体转染入HeLa细胞后，以及与异源启动子胸苷激酶融合的合成寡核苷酸转染入HeLa细胞后，已被定位到近端启动子中-107至-55碱基对（bp）的一个52碱基对DNA片段上。该52聚体序列包含所有Ⅱ类基因中保守的X盒和Y盒元件；它们的存在对于IFN-γ诱导是必不可少的。此外，DPA基因X盒紧邻的5'端额外5个碱基对对于IFN-γ诱导是必要且充分的。该区域可能包含一个IFN-γ反应元件。在另外三个经过充分研究的Ⅱ类基因启动子的关键缺失位点附近也发现了一个密切相关的序列，所有这些启动子在X盒的5'端都需要长得多的序列。第四个元件，即W元件，在所有Ⅱ类基因中位于X盒5'端约15个碱基对处，显然对DPA基因的IFN-γ诱导作用不大。
