DEC1 modulates the circadian phase of clock gene expression
DEC1 modulates the circadian phase of clock gene expression
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DOI：
10.1128/mcb.02168-07
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发表时间：
2008-06-01
影响因子：
5.3
通讯作者：
Kato, Yukio
中科院分区：
文献类型：
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作者：
Nakashima, Ayumu;Kawamoto, Takeshi;Kato, Yukio
DEC 1抑制CLOCK/BMAL 1增强的启动子活性，但其在哺乳动物昼夜节律系统中的作用仍不清楚。在这里，我们研究了Dec 1过表达或缺乏对50%血清触发的昼夜节律基因表达的影响。Dec 1的过表达延迟了Dec 1、Dec 2、Per 1和Dbp等在其调控区含有E盒的时钟基因的时相，而对Per 2和Cry 1携带CACGTT E'盒的昼夜节律时相几乎没有影响。相反，Dec 1缺乏使含E-box的时钟基因的相位提前，但不使含E '-box的时钟基因的相位提前。因此，在染色质免疫沉淀、电泳迁移率改变和荧光素酶报告基因测定中，DEC 1在E盒上显示出强结合和反式阻遏，但在E'盒上没有。Dec 1（-/-）小鼠表现出行为节律，在恒定黑暗和更快的再夹带条件下，昼夜节律周期略长，但显着更长，以6小时的相位提前转变的光暗周期。用小干扰RNA敲低Dec 2使Dec 1和Dbp的表达期提前，并且Dec 1和Dec 2的双敲低对含E-box的时钟基因的表达有更强的影响。这些发现表明，DEC 1，沿着与DEC 2，在分子钟的精细调节和鲁棒性中发挥作用。
DEC1 suppresses CLOCK/BMAL1-enhanced promoter activity, but its role in the circadian system of mammals remains unclear. Here we examined the effect of Dec1 overexpression or deficiency on circadian gene expression triggered with 50% serum. Overexpression of Dec1 delayed the phase of clock genes such as Dec1, Dec2, Per1, and Dbp that contain E boxes in their regulatory regions, whereas it had little effect on the circadian phase of Per2 and Cry1 carrying CACGTT E' boxes. In contrast, Dec1 deficiency advanced the phase of the E-box-containing clock genes but not that of the E'-box-containing clock genes. Accordingly, DEC1 showed strong binding and transrepression on the E box, but not on the E' box, in chromatin immunoprecipitation, electrophoretic mobility shift, and luciferase reporter assays. Dec1(-/-) mice showed behavioral rhythms with slightly but significantly longer circadian periods under conditions of constant darkness and faster reentrainment to a 6-h phase-advanced shift of a light-dark cycle. Knockdown of Dec2 with small interfering RNA advanced the phase of Dec1 and Dbp expression, and double knockdown of Dec1 and Dec2 had much stronger effects on the expression of the E-box-containing clock genes. These findings suggest that DEC1, along with DEC2, plays a role in the finer regulation and robustness of the molecular clock.