Functional analysis of mouse 3-phosphoglycerate dehydrogenase (Phgdh) gene promoter in developing brain
Functional analysis of mouse 3-phosphoglycerate dehydrogenase (Phgdh) gene promoter in developing brain
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DOI：
10.1002/jnr.20102
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发表时间：
2004-06-01
影响因子：
4.2
通讯作者：
Suzuki, Y
中科院分区：
文献类型：
--
作者：
Shimizu, M;Furuya, S;Suzuki, Y
D-3-磷酸甘油酸脱氢酶（Phgdh; EC www.example.com）是通过磷酸化途径从头合成L-丝氨酸所必需的酶。有针对性地破坏小鼠Phgdh基因已被证明会导致胚胎死亡，伴随着大脑发育的严重异常。phgdh在发育中的脑中仅由神经上皮和放射状胶质细胞表达，随后主要由星形胶质细胞表达。为了阐明调控Phgdh在发育中的脑中的这种细胞类型特异性表达的分子机制，在原代培养物和转基因小鼠中表征了携带启动子的基因的上游3.5-磷酸酶对（kbp）区域。转染培养物中Phgdh 5 '巢式缺失的分析表明，神经胶质培养物中的总体报告荧光素酶水平高于神经元培养物中的水平。尽管在神经胶质和神经元培养物中，该基因的基础启动子活性似乎依赖于位于-193和-184之间的Sp1结合序列，但位于-1，794和-1，095之间的上游5 '侧翼区以神经胶质细胞特异性方式促进Phgdh转录的上调。在转基因小鼠胚胎的大脑皮层中，含有-1，794/+4启动子序列的Phgdh启动子-LacZ转基因DNA指导β-半乳糖苷酶（β-Gal）的表达主要在Phgdh阳性神经上皮和放射状胶质细胞中。当β-Gal表达仅由上游0.2 kbp最小启动子驱动时，这种胶质细胞偏好减弱。然而，通过将700个碱基对的5'-DNA片段置于最小启动子的上游，β-Gal表达的神经胶质偏好得以恢复。这些观察结果表明存在顺式作用元件，赋予Phgdh转录在远端启动子区域的细胞类型特异性。(C)2004威利-利斯公司
D-3-Phosphoglycerate dehydrogenase (Phgdh; EC 1.1.1.95) is a necessary enzyme for de novo L-serine biosynthesis via the phosphorylated pathway. Targeted disruption of the mouse Phgdh gene has been shown to result in embryonic lethality, accompanied by severe abnormalities in brain development. Phgdh is expressed exclusively by neuroepithelium and radial glia in developing brain and later mainly by astrocytes. To elucidate the molecular mechanism that regulates such cell-type-specific expression of Phgdh in developing brain, an upstream 3.5-kilobase-pair (kbp) region of the gene harboring the promoter was characterized in primary cultures and transgenic mice. Analysis of Phgdh 5'-nested deletions in transfected cultures indicated that overall reporter luciferase levels were higher in glial cultures than those in neuronal cultures. Although basal promoter activity of the gene appeared to depend on an Sp1 binding sequence residing between -193 and -184 in both glial and neuronal cultures, an upstream 5'-flanking region between -1,794 and -1,095 contributed to up-regulation of Phgdh transcription in a glial-cell-specific manner. In the cerebral cortex of transgenic mouse embryos, the Phgdh promoter-LacZ transgene DNA containing -1,794/+4 promoter sequences directed beta-galactosidase (beta-Gal) expression mainly to Phgdh-positive neuroepithelium and radial glia. This glial preference diminished when beta-Gal expression was driven solely by the upstream 0.2-kbp minimal promoter. However, glial preference of beta-Gal expression was restored by placing the 700-base-pair 5'-DNA segment upstream of the minimal promoter. These observations suggest the presence of cis-acting elements that confer the cell type specificity of Phgdh transcription in the distal promoter region. (C) 2004 Wiley-Liss, Inc.