Liska D J, Slack J L, Bornstein P
Department of Biochemistry, University of Washington, Seattle 98195.
Cell Regul. 1990 May;1(6):487-98. doi: 10.1091/mbc.1.6.487.
The first intron of the human alpha 1(I) collagen gene contains a positive, orientation-dependent cis-acting sequence located between bases +292 and +670. Transient transfection experiments indicate that this sequence is functional in both primary chicken tendon fibroblasts and in a human fibroblast-like cell line derived from SV40-transformed marrow stromal cells. DNase I footprint, methylation interference, and mobility shift analyses provide evidence for a sequence-specific binding activity and show that the region of binding corresponds to a 29-base-pair sequence that is also present in the rat alpha 1(I) collagen intron. This conserved sequence contains an AP1 consensus motif. Sequence-specific binding activity is present in nuclear extracts from HeLa and fibroblast cell lines but not in extracts from two lymphoid cell lines. Mutation of the AP1 consensus sequence indicates that this motif is required for function of the cis-acting element. These data indicate that transcriptional modulation of the alpha 1(I) collagen gene involves an interaction between an intronic AP1-containing sequence and its cognate transcription factors.
人类α1（I）型胶原基因的第一个内含子包含一个正向、依赖方向的顺式作用序列，位于碱基+292至+670之间。瞬时转染实验表明，该序列在原代鸡肌腱成纤维细胞以及源自SV40转化的骨髓基质细胞的人成纤维细胞样细胞系中均具有功能。DNase I足迹分析、甲基化干扰分析和迁移率变动分析为序列特异性结合活性提供了证据，并表明结合区域对应于一个29个碱基对的序列，该序列也存在于大鼠α1（I）型胶原内含子中。这个保守序列包含一个AP1共有基序。序列特异性结合活性存在于HeLa细胞系和成纤维细胞系的核提取物中，但不存在于两个淋巴细胞系的提取物中。AP1共有序列的突变表明该基序是顺式作用元件功能所必需的。这些数据表明，α1（I）型胶原基因的转录调控涉及一个内含子中含AP1的序列与其同源转录因子之间的相互作用。
