Chilov D, Hofer T, Bauer C, Wenger R H, Gassmann M
Institutes of Physiology and Veterinary Physiology, University of Zürich, CH-8057 Zürich, Switzerland.
FASEB J. 2001 Dec;15(14):2613-22. doi: 10.1096/fj.01-0092com.
The key elements of circadian clockwork and oxygen homeostasis are the PAS protein family members PER and CLOCK and hypoxia-inducible factor 1alpha (HIF-1alpha). The PAS domain serves as an interface for protein-protein interactions. We asked whether a cross-talk exists between the PAS components of hypoxic and circadian pathways. We found several isoforms of PER1 protein that exhibit tissue-specific size differences. In the mouse brain, a predominantly nuclear 48 kDa isoform that followed a daily rhythm was observed. The 48 kDa form was found in the nuclear fractions derived from mouse liver, Swiss3T3 fibroblasts, and N2A neuroblastoma cells. In mouse kidney and human 293 kidney cells, a 55 kDa PER1 form was detected. CLOCK was observed as a predicted 100 kDa protein in rat-1 cells and in all analyzed mouse tissues including brain, liver, kidney, and spleen. In contrast to PER1, CLOCK protein expression was not rhythmic. Exposure to hypoxia led to increased PER1 and CLOCK protein levels in mice. Based on coimmunoprecipitation experiments that showed protein-protein interaction between PER1 and the alpha subunit of HIF-1, we suggest that these hypoxic effects may be modulated by HIF-1alpha.-Chilov, D., Hofer, T., Bauer, C., Wenger, R. H., Gassmann, M. Hypoxia affects expression of circadian genes PER1 and CLOCK in mouse brain.
生物钟机制和氧稳态的关键要素是PAS蛋白家族成员PER和CLOCK以及缺氧诱导因子1α（HIF-1α）。PAS结构域作为蛋白质-蛋白质相互作用的界面。我们探究了缺氧途径和生物钟途径的PAS成分之间是否存在相互作用。我们发现了几种PER1蛋白的异构体，它们表现出组织特异性的大小差异。在小鼠大脑中，观察到一种主要位于细胞核的48 kDa异构体，其呈现出每日节律。在源自小鼠肝脏、Swiss3T3成纤维细胞和N2A神经母细胞瘤细胞的细胞核组分中发现了48 kDa的形式。在小鼠肾脏和人293肾细胞中，检测到一种55 kDa的PER1形式。在大鼠-1细胞以及包括脑、肝、肾和脾在内的所有分析的小鼠组织中，CLOCK被观察为一种预测的100 kDa蛋白。与PER1不同，CLOCK蛋白表达没有节律性。暴露于缺氧环境会导致小鼠体内PER1和CLOCK蛋白水平升高。基于共免疫沉淀实验显示PER1与HIF-1的α亚基之间存在蛋白质-蛋白质相互作用，我们认为这些缺氧效应可能受HIF-1α调节。-奇洛夫，D.，霍费尔，T.，鲍尔，C.，温格，R.H.，加斯曼，M.缺氧影响小鼠脑中生物钟基因PER1和CLOCK的表达。
