Gimble J M, Hua X, Wanker F, Morgan C, Robinson C, Hill M R, Nadon N
Immunobiology and Cancer Program, Oklahoma Medical Research Foundation, Oklahoma City.
Am J Physiol. 1995 Feb;268(2 Pt 1):E213-8. doi: 10.1152/ajpendo.1995.268.2.E213.
Lipoprotein lipase, an enzyme of central importance to lipid metabolism, is most abundant in adipose tissues, cardiac and skeletal muscle, and portions of the brain. The current work examined the murine lipoprotein lipase promoter using transient transfection, gel-retention analyses, and transgenic mice. Maximum expression of the luciferase reporter gene in transfected cells was observed with -101 bp of the promoter. Nuclear extracts from tissues expressing lipoprotein lipase contained DNA binding proteins that recognize the CCAAT box (-64 bp) and an octamer motif (-46 bp); this combination of factors was absent in nonexpressing tissues. Transgenic mice from three of five founders prepared with -1,824-bp promoter constructs expressed the luciferase reporter gene at highest levels in brown adipose tissue and brain. These findings suggest that the -1,824-bp promoter region contains sequence elements responsible for the tissue-specific transcription of lipoprotein lipase in vivo.
脂蛋白脂肪酶是脂质代谢中至关重要的一种酶,在脂肪组织、心肌和骨骼肌以及部分脑区中含量最为丰富。目前的研究工作利用瞬时转染、凝胶滞留分析和转基因小鼠对小鼠脂蛋白脂肪酶启动子进行了检测。在转染细胞中,当启动子的 -101 bp 片段存在时,观察到荧光素酶报告基因的表达量最高。表达脂蛋白脂肪酶的组织的核提取物中含有能识别 CCAAT 盒(-64 bp)和八聚体基序(-46 bp)的 DNA 结合蛋白;在不表达该酶的组织中则不存在这种因子组合。用 -1,824-bp 启动子构建体制备的五只转基因小鼠奠基者中有三只,其荧光素酶报告基因在棕色脂肪组织和脑中表达水平最高。这些发现表明,-1,824-bp 启动子区域包含负责脂蛋白脂肪酶在体内组织特异性转录的序列元件。