The PAS/LOV protein VIVID controls temperature compensation of circadian clock phase and development in Neurospora crassa
The PAS/LOV protein VIVID controls temperature compensation of circadian clock phase and development in Neurospora crassa
复制标题
DOI：
10.1101/gad.437107
复制
发表时间：
2007-08-01
影响因子：
10.5
通讯作者：
Heintzen, Christian
中科院分区：
文献类型：
--
作者：
Hunt, Suzanne M.;Elvin, Mark;Heintzen, Christian
生物钟是细胞的计时器，在日常和季节的时间尺度上调节时间组织的各个方面。为了实现精确的时间测量，时钟的周期长度在一定的温度范围内保持不变，这种现象称为温度补偿。生物钟周期的温度补偿有助于维持时钟控制事件的稳定“目标时间”或相位。在这里，我们表明，脉孢菌蛋白VIVID（VVD）缓冲昼夜节律系统对温度波动。在vvd无效突变体中，生物钟控制的事件（如无性孢子形成（分生孢子））的昼夜节律周期是温度补偿的，但这个时钟时间标记的相位不是。与vvd（KO）菌株在较低温度下的延迟分生孢子一致，野生型中vvd基因产物的水平随着温度降低而增加。此外，缺乏VVD光功能的vVD（C108 A）突变体保持了短暂影响分生孢子阶段的暗活性，表明VVD影响时钟下游的分生孢子时间。频率（FRQ）磷酸化在vvdKO菌株中改变，表明VVD可以影响黑暗中时钟控制过程的时间的机制。因此，时钟控制输出的温度补偿是维持整个昼夜节律系统的温度补偿的关键因素。
Circadian clocks are cellular timekeepers that regulate aspects of temporal organization on daily and seasonal time scales. To allow accurate time measurement, the period lengths of clocks are conserved in a range of temperatures-a phenomenon known as temperature compensation. Temperature compensation of circadian clock period aids in maintaining a stable "target time" or phase of clock-controlled events. Here we show that the Neurospora protein VIVID (VVD) buffers the circadian system against temperature fluctuations. In vvd-null mutants, the circadian period of clock-controlled events such as asexual sporulation (conidiation) is temperature compensated, but the phase of this clock time marker is not. Consistent with delayed conidiation at lower temperatures in vvd(KO) strains, the levels of vvd gene products in the wild type increase with decreasing temperatures. Moreover, vvd(C108A) mutants that lack the light function of VVD maintain a dark activity that transiently influences the phase of conidiation, indicating that VVD influences the time of conidiation downstream from the clock. FREQUENCY (FRQ) phosphorylation is altered in a vvdKO strain, suggesting a mechanism by which VVD can influence the timing of clock-controlled processes in the dark. Thus, temperature compensation of clock-controlled output is a key factor in maintaining temperature compensation of the entire circadian system.