昼夜节律
中文名称
通路描述
昼夜节律是一种内部生物钟，能够在没有环境线索的情况下维持约 24 小时的节律。在哺乳动物中，昼夜节律机制由细胞自主的转录 - 翻译反馈环路驱动，驱动核心时钟组件的 24 小时节律表达。第一个负反馈环路是周期基因（PER1, PER2, 和 PER3）和 cryptochrome 基因（CRY1 和 CRY2）的节律性转录。PER 和 CRY 蛋白形成异二聚体，作用于 CLOCK/BMAL1 异二聚体以抑制其自身转录。PER 和 CRY 蛋白由酪氨酸激酶 epsilon（CKIepsilon）磷酸化，导致降解和循环重启。第二个环路是由 CLOCK/BMAL1 异二聚体驱动的积极反馈环路，启动含有 E-box 顺式调控增强子序列的靶基因转录。
英文描述
Circadian rhythm is an internal biological clock, which enables to sustain an approximately 24-hour rhythm in the absence of environmental cues. In mammals, the circadian clock mechanism consists of cell-autonomous transcription-translation feedback loops that drive rhythmic, 24-hour expression patterns of core clock components. The first negative feedback loop is a rhythmic transcription of period genes (PER1, PER2, and PER3) and chryptochrome genes (CRY1 and CRY2). PER and CRY proteins form a heterodimer, which acts on the CLOCK/BMAL1 heterodimer to repress its own transcription. PER and CRY proteins are phosphorylated by casein kinase epsilon (CKIepsilon), which leads to degradation and restarting of the cycle. The second loop is a positive feedback loop driven by the CLOCK/BMAL1 heterodimer, which initiates transcription of target genes containing E-box cis-regulatory enhancer sequences.
所含基因
34 个基因