Okino Nozomu, Mori Kaoru, Ito Makoto
Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, 812-8581, Fukuoka, Japan.
Biochem Biophys Res Commun. 2002 Nov 22;299(1):160-6. doi: 10.1016/s0006-291x(02)02540-8.
We report here the molecular cloning of the mouse neutral ceramidase gene and its promoter analysis. The gene, composed of 27 exons ranging in size from 40 to 292 bp, spans more than 70 kb. Analysis of the 5(')-flanking region of the ceramidase genes revealed that the first exon of the gene of mouse liver was exactly the same as that of mouse kidney and Swiss 3T3 fibroblasts but completely different from that of mouse brain. The putative promoter regions of liver and brain ceramidase genes contained several well-characterized promoter elements such as GATA-2, C/EBP, and HNF3beta but lacked TATA and CAAT boxes, a typical feature of a housekeeping gene, although the expression is regulated in a tissue-specific manner. Interestingly, a GC box was exclusively found in the putative promoter of mouse liver whereas potential AP1 and AP4 binding sites were present in that of mouse brain. By a luciferase reporter gene assay, it was shown that the GC-rich region, which exists just upstream of the first exon, conferred the promoter activity in Swiss 3T3 cells.
我们在此报告小鼠中性神经酰胺酶基因的分子克隆及其启动子分析。该基因由27个外显子组成，大小从40到292 bp不等，跨度超过70 kb。对神经酰胺酶基因5′侧翼区域的分析表明，小鼠肝脏基因的第一个外显子与小鼠肾脏和瑞士3T3成纤维细胞的完全相同，但与小鼠大脑的完全不同。肝脏和大脑神经酰胺酶基因的推定启动子区域包含几个特征明确的启动子元件，如GATA-2、C/EBP和HNF3β，但缺乏TATA和CAAT框，这是管家基因的典型特征，尽管其表达是以组织特异性方式调节的。有趣的是，GC框仅在小鼠肝脏的推定启动子中发现，而潜在的AP1和AP4结合位点存在于小鼠大脑的推定启动子中。通过荧光素酶报告基因测定表明，存在于第一个外显子上游的富含GC的区域赋予了瑞士3T3细胞中的启动子活性。
