Ohashi Sachiyo, Fukumura Reiko, Higuchi Takashi, Kobayashi Shunsuke
Research Unit of Biochemistry, College of Pharmacy, Nihon University, 7-7-1, Narashinodai, Funabashi, Chiba 274-8555, Japan.
Mol Cell Biochem. 2009 Jul;327(1-2):267-75. doi: 10.1007/s11010-009-0065-x. Epub 2009 Feb 19.
YB-1 controls gene expression at both the transcriptional and translational levels. In the brain, a high level of YB-1 is expressed from prior to the first week after birth. However, YB-1 expression substantially declines to the adult level thereafter. Here, we investigated the regulatory mechanism of YB-1 transcription in the postnatal brain. We found that an E-box sequence within the 5'-untranslated region (5'-UTR) of the gene was recognized by Math2 in the 5-day-old brain, whereas the DNA binding was reduced in the 4-week-old brain. In vitro transcription analysis and reporter gene assay revealed that Math2 was necessary for YB-1 transcription. Furthermore, the expression pattern of Math2 protein in the postnatal brain was correlated with that of YB-1 protein. Our results suggest that YB-1 transcription in the postnatal brain is regulated by Math2, which binds to an E-box in the 5'-UTR of the YB-1 gene.
YB-1在转录和翻译水平上都控制着基因表达。在大脑中，出生后第一周之前YB-1就有高水平表达。然而，此后YB-1表达大幅下降至成年水平。在此，我们研究了出生后大脑中YB-1转录的调控机制。我们发现该基因5'-非翻译区（5'-UTR）内的一个E-box序列在出生5天的大脑中被Math2识别，而在出生4周的大脑中DNA结合减少。体外转录分析和报告基因检测表明Math2是YB-1转录所必需的。此外，Math2蛋白在出生后大脑中的表达模式与YB-1蛋白的表达模式相关。我们的结果表明，出生后大脑中YB-1的转录受Math2调控，Math2与YB-1基因5'-UTR中的一个E-box结合。
