Circadian phosphorylation of ATF-2, a potential activator of Period2 gene transcription in the chick pineal gland
Circadian phosphorylation of ATF-2, a potential activator of Period2 gene transcription in the chick pineal gland
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DOI：
10.1111/j.1471-4159.2007.04900.x
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发表时间：
2007-12-01
影响因子：
4.7
通讯作者：
Fukada, Yoshitaka
中科院分区：
文献类型：
--
作者：
Shimizu, Fumiko;Fukada, Yoshitaka
刺激诱导的Period基因转录是脊椎动物昼夜节律系统相移的关键步骤。鸡Period2 的启动子区域含有典型的钙/cAMP 响应元件，但其功能相关性尚不清楚。本研究表明，cAMP 响应元件结合蛋白 (CREB) 和激活转录因子 2 (ATF-2) 与小鸡松果体中的 period2 基因的启动子区域结合。在瞬时转染测定中，含有鸡Period2 0.7-kbp上游区域的报告构建体被ATF-2反式激活，但它对CREB的反应很差。在小鸡松果体中，CREB 蛋白在激酶诱导域的磷酸化受到光的负调控。另一方面，ATF-2 在氨基末端反式激活结构域的磷酸化表现出昼夜节律，并在白天出现峰值，表明 ATF-2 在雏鸡松果体的昼夜节律中发挥作用。
Stimulus-induced transcription of the Period gene is a critical step for phase-shift of vertebrate circadian systems. The promoter region of chicken Period2 contains a canonical calcium/cAMP-responsive element, but its functional relevance is not known. The present study shows that cAMP-responsive element-binding protein (CREB) and activating transcription factor-2 (ATF-2) bind to the promoter region of the Period2 gene in the chick pineal gland. In transient transfection assays, a reporter construct containing 0.7-kbp upstream region of chicken Period2 was transactivated by ATF-2, but it was poorly responsive to CREB. In the chick pineal gland, phosphorylation of CREB protein at the kinase-inducible domain was negatively regulated by light. On the other hand, phosphorylation of ATF-2 at the amino-terminal transactivation domain exhibited a circadian rhythm with a daytime peak, suggesting a role for ATF-2 in circadian rhythmicity in the chick pineal gland.