THE CHICKEN LYSOZYME-5' MATRIX ATTACHMENT REGION INCREASES TRANSCRIPTION FROM A HETEROLOGOUS PROMOTER IN HETEROLOGOUS CELLS AND DAMPENS POSITION EFFECTS ON THE EXPRESSION OF TRANSFECTED GENES
THE CHICKEN LYSOZYME-5' MATRIX ATTACHMENT REGION INCREASES TRANSCRIPTION FROM A HETEROLOGOUS PROMOTER IN HETEROLOGOUS CELLS AND DAMPENS POSITION EFFECTS ON THE EXPRESSION OF TRANSFECTED GENES
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DOI：
10.1128/mcb.10.5.2302
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发表时间：
1990-05-01
影响因子：
5.3
通讯作者：
STRATLING, WH
中科院分区：
文献类型：
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作者：
PHIVAN, L;VONKRIES, JP;STRATLING, WH
基质附着区（MARs）是一种DNA元件，通过与染色体骨架结合，将基因组分解为拓扑分离的结构域。本研究探讨了位于鸡溶菌酶基因5”的MAR对异源基因在异源细胞系统中表达的可能影响。将单纯疱疹病毒胸苷激酶启动子（TC）控制的氯霉素乙酰转移酶（CAT）指示基因构建体和鸡溶菌酶5“MARs （MTCM）两侧相同转录单元的构建体稳定转染大鼠成纤维细胞后，检测其表达情况。每个拷贝数中位CAT活性在MTCM中比在TC中提高了大约10倍。标准化CAT活性的总变异从TC的100倍以上下降到MTCM的近6倍。S1核酸酶和连续转录试验分别表明，MTCM转染物的稳态转录水平和相对转录率均有所提高。因此，鸡溶菌酶5'' MAR可以通过增加转录RNA聚合酶分子的密度，在不同物种的细胞中提高异源启动子的表达，减少位置依赖性。MARs介导的转录增强表明MARs对基因表达很重要，而不仅仅是DNA包装。
Matrix attachment regions (MARs) are DNA elements that dissect the genome into topologically separated domains by binding to a chromosomal skeleton. This study explored the putative influence of the MAR located 5'' of the chicken lysozyme gene on expression of heterologous genes in heterologous cell systems. Expression of a construct with the chloramphenicol acetyltransferase (CAT) indicator gene controlled by the herpes simplex virus thymidine kinase promoter (TC) and a construct in which the same transcriptional unit is flanked by chicken lysozyme 5'' MARs (MTCM) was assayed after stable transfection into rat fibroblasts. Median CAT activity per copy number in MTCM transfectants was elevated approximately 10-fold relative to that in TC transfectants. Total variation in normalized CAT activity decreased from more than 100-fold among TC transfectants to nearly 6-fold among MTCM transfectants. The steady-state level of transcripts and the relative rate of transcription were increased in MTCM transfectants, as shown by S1 nuclease and run-on transcription assays, respectively. The chicken lysozyme 5'' MAR thus can confer elevated, less position-dependent expression on a heterologous promoter in cells of a different species by increasing the density of transcribing RNA polymerase molecules. MAR-mediated transcriptional enhancment suggests that MARs are important for gene expression and not just for DNA packaging.