Chen Chia-Yang, Chang Chung-Han, Wu Chien-Han, Tu Yi-Tsung, Wu Keqiang
Institute of Plant Biology, National Taiwan University, Taipei, 10617, Taiwan.
Plant J. 2022 Dec;112(6):1462-1472. doi: 10.1111/tpj.16027. Epub 2022 Nov 24.
Histone deacetylases (HDAs) regulate many aspects of plant development and responses to environmental changes. Previous studies have demonstrated that the Arabidopsis histone deacetylase HDA15 is a positive regulator in far-red (FR) light-mediated inhibition of hypocotyl elongation. Furthermore, HDA15 can be phosphorylated and its enzymatic activity is negatively regulated by phosphorylation. However, the kinases that can phosphorylate HDA15 are still unknown. Cyclin-dependent kinases (CDKs) are a large family of serine/threonine protein kinases and have been identified as major regulators of the cell cycle and transcription. In this study, we show that the cyclin-dependent kinase CDKC2 interacts with HDA15 both in vitro and in vivo. In vitro kinase assays show that CDKC2 phosphorylates HDA15. Genetic evidence suggests that HDA15 acts downstream of CDKC2 in hypocotyl elongation under FR light. Furthermore, HDA15 and CDKC2 function synergistically in the regulation of FR-mediated cell elongation. The expression of cell wall organization- and auxin signaling-related genes under FR light is increased in hda15 and cdkc2/hda15 mutants. Taken together, our study indicates that CDKC2 can phosphorylate HDA15 and plays an important role in FR light-regulated hypocotyl elongation.
组蛋白去乙酰化酶（HDAs）调控植物发育的诸多方面以及对环境变化的响应。先前的研究表明，拟南芥组蛋白去乙酰化酶HDA15是远红光（FR）介导的下胚轴伸长抑制中的一个正向调节因子。此外，HDA15可以被磷酸化，其酶活性受到磷酸化的负调控。然而，能够磷酸化HDA15的激酶仍然未知。细胞周期蛋白依赖性激酶（CDKs）是丝氨酸/苏氨酸蛋白激酶的一个大家族，已被确定为细胞周期和转录的主要调节因子。在本研究中，我们表明细胞周期蛋白依赖性激酶CDKC2在体外和体内均与HDA15相互作用。体外激酶分析表明CDKC2使HDA15磷酸化。遗传学证据表明，在FR光下，HDA15在CDKC2下游参与下胚轴伸长。此外，HDA15和CDKC2在FR介导的细胞伸长调节中协同发挥作用。在hda15和cdkc2/hda15突变体中，FR光下细胞壁组织和生长素信号相关基因的表达增加。综上所述，我们的研究表明CDKC2可以使HDA15磷酸化，并在FR光调控的下胚轴伸长中发挥重要作用。
