Temperature regulation of circadian clock proteins from Chlamydomonas and their relevance for entrainment by temperature cycles

点击翻译按钮获取中文摘要

Beside light-dark, temperature cycles are one of the main environmental cues that synchronize circadian clocks to a period of 24h. For control of entrainment by temperature cycles, certain clock components should be able to respond to changes of temperature within the physiological range. We have recently found that several clock-relevant proteins of the green alga Chlamydomonas reinhardtii can integrate temperature information and that their temperature-dependent regulation is interconnected. These proteins include the C1 and C3 subunits of the RNA-binding protein CHLAMY1, casein kinase1 (CK1) and protein phosphatases PP2A and/or PP5. They are differentially expressed, modified and/or active at different temperatures (18 and 28ºC) that differ in 10ºC, but are in the physiological range of Chlamydomonas. Alterations of the temperature regulation of some of these components that have been conducted so far resulted in disturbances of the synchronization of the circadian clock by temperature cycles. In this study, we aim to further examine the temperature-controlled molecular clock network. We want to identify and functionally characterize some of the responsible trans-acting factors, up-regulating c3 at 18ºC and ck1 at 28ºC and examine their role in entrainment by temperature cycles.