Somers D E, Schultz T F, Milnamow M, Kay S A
The Scripps Research Institute, Department of Cell Biology, La Jolla, California 92037, USA.
Cell. 2000 Apr 28;101(3):319-29. doi: 10.1016/s0092-8674(00)80841-7.
We have conducted genetic screens for period length mutants in Arabidopsis using a transgenic bioluminescence phenotype. This screen identified mutations at a locus, ZEITLUPE (ZTL), that lengthen the free-running period of clock-controlled gene transcription and cell expansion, and alter the timing of the daylength-dependent transition from vegetative to floral development. Map-based cloning of ZTL identified a novel 609 amino acid polypeptide consisting of an amino-terminal PAS domain, an F box and six carboxy-terminal kelch repeats. The PAS region is highly similar to the PAS domain of the Arabidopsis blue-light receptor NPH1, and the Neurospora circadian-associated protein WHITE COLLAR-1 (WC-1). The striking fluence rate-dependent effect of the ztl mutations suggests that ZTL plays a primary role in the photocontrol of circadian period in higher plants.
我们利用转基因生物发光表型对拟南芥的周期长度突变体进行了遗传筛选。该筛选在一个名为ZEITLUPE（ZTL）的位点鉴定出了突变，这些突变延长了生物钟控制的基因转录和细胞扩张的自由运转周期，并改变了依赖日长的从营养生长到生殖发育转变的时间。通过基于图谱的克隆鉴定出ZTL是一种新的609个氨基酸的多肽，它由一个氨基端的PAS结构域、一个F盒和六个羧基端的kelch重复序列组成。PAS区域与拟南芥蓝光受体NPH1以及粗糙脉孢菌生物钟相关蛋白WHITE COLLAR-1（WC-1）的PAS结构域高度相似。ztl突变体显著的光通量率依赖性效应表明，ZTL在高等植物昼夜节律周期的光控中起主要作用。
