Bornstein P
Department of Biochemistry University of Washington, Seattle, Washington, USA.
Matrix Biol. 1996 Apr;15(1):3-10. doi: 10.1016/s0945-053x(96)90121-3.
The transcriptional regulation of the genes encoding the alpha 1 (I) collagen chains is necessarily complex since these genes are expressed at widely different levels, and in a cell- and tissue-specific fashion. In the case of the alpha 1 (I) gene, there is substantial, but controversial, evidence for an involvement of the first intron in the tissue-specific expression of the gene. This evidence is based largely on transfection of cells with collagen-reporter gene constructs and on studies of transgenic mice. In this review, I propose a number of reason for the conflicting data in the literature: 1) the cell-specific nature of the intronic effect; thus, not all cultured, collagen-synthesizing cells will demonstrate an intronic effect by transfection; 2) the possibility that functionally equivalent regulatory elements are placed in different regions of the alpha 1 (I) gene in different species; and 3) the possibility that functionally redundant sequences exist within the alpha 1 (I) gene, which would permit other regions to substitute for the first intron.
编码α1（I）型胶原链的基因的转录调控必然很复杂，因为这些基因的表达水平差异很大，且以细胞和组织特异性的方式进行表达。就α1（I）基因而言，有大量但存在争议的证据表明第一个内含子参与了该基因的组织特异性表达。这些证据主要基于用胶原报告基因构建体转染细胞以及对转基因小鼠的研究。在这篇综述中，我提出了文献中数据相互矛盾的一些原因：1）内含子效应的细胞特异性性质；因此，并非所有培养的、合成胶原的细胞通过转染都会表现出内含子效应；2）在不同物种中，功能等效的调控元件可能位于α1（I）基因的不同区域；3）α1（I）基因内可能存在功能冗余序列，这会使其他区域能够替代第一个内含子。
