Out of the dark: how the PIFs are unmasking a dual temporal mechanism of phytochrome signalling
Out of the dark: how the PIFs are unmasking a dual temporal mechanism of phytochrome signalling
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DOI：
10.1093/jxb/erm186
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发表时间：
2007-10-01
影响因子：
6.9
通讯作者：
Quail, Peter H.
中科院分区：
文献类型：
--
作者：
Monte, Elena;Al-Sady, Bassem;Quail, Peter H.
光诱导核转位后，光敏色素诱导基因表达的变化来调节植物的发育。PIF 3和其他PIFs（光敏色素相互作用因子）是bHLH（碱性螺旋-环-螺旋）转录调节因子家族的成员，它们与光敏色素分子的活性Pfr构象体特异性相互作用，表明PIFs是光敏色素信号转导的关键组分。PIF抑制光敏色素信号的机制尚不清楚。在最初的研究表明PIF 3是光敏色素信号传导的正调节剂之后，突变体研究表明PIFs主要在该途径中充当负调节剂。此外，在某些情况下，它们在黑暗中积累，并在光照下被泛素-26S蛋白酶体系统降解。至少对于PIF 3，蛋白质降解依赖于与光敏色素分子的直接相互作用，并且在蛋白质磷酸化之前。在这篇综述中，目前的理解的PIFs在光敏色素介导的光形态建成的作用将进行总结，并最近的研究结果表明一个意想不到的双重机制的PIFs的行动将进行讨论。
Following light-induced nuclear translocation, the phytochromes induce changes in gene expression to regulate plant development. PIF3 and other PIFs (phytochrome-interacting factors), members of the bHLH (basic helix-loop-helix) family of transcriptional regulators, interact specifically with the active Pfr conformer of the phytochrome molecule, suggesting that the PIFs are key components of phytochrome signal transduction. The mechanism by which the PIFs transduce phytochrome signals is not understood. After initial studies that suggested that PIF3 was a positive regulator of phytochrome signalling, mutant studies indicated that the PIFs primarily act as negative regulators in the pathway. Furthermore, in some cases they accumulate in the dark and are degraded upon illumination by the ubiquitin-26S proteasome system. At least for PIF3, the protein degradation depends on direct interaction with the phytochrome molecule and is preceded by protein phosphorylation. In this review, the current understanding of the role of the PIFs in phytochrome-mediated photomorphogenesis will be summarized, and recent findings suggesting an unanticipated dual mechanism of action of the PIFs will be discussed.