Max F. Perutz Laboratories, Medical University of Vienna, Vienna Biocenter, Dr Bohr-Gasse 9/3, A-1030, Wien, Austria.
Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, SY23 3EB, UK.
Plant J. 2018 Jun;94(6):1010-1022. doi: 10.1111/tpj.13914. Epub 2018 May 10.
The ability to adapt growth and development to temperature variations is crucial to generate plant varieties resilient to predicted temperature changes. However, the mechanisms underlying plant response to progressive increases in temperature have just started to be elucidated. Here, we report that the cyclin-dependent kinase G1 (CDKG1) is a central element in a thermo-sensitive mRNA splicing cascade that transduces changes in ambient temperature into differential expression of the fundamental spliceosome component, ATU2AF65A. CDKG1 is alternatively spliced in a temperature-dependent manner. We found that this process is partly dependent on both the cyclin-dependent kinase G2 (CDKG2) and the interacting co-factor CYCLIN L1 (CYCL1), resulting in two distinct messenger RNAs. The relative abundance of both CDKG1 transcripts correlates with ambient temperature and possibly with different expression levels of the associated protein isoforms. Both CDKG1 alternative transcripts are necessary to fully complement the expression of ATU2AF65A across the temperature range. Our data support a previously unidentified temperature-dependent mechanism based on the alternative splicing (AS) of CDKG1 and regulated by CDKG2 and CYCL1. We propose that changes in ambient temperature affect the relative abundance of CDKG1 transcripts, and this in turn translates into differential CDKG1 protein expression coordinating the AS of ATU2AF65A.
适应温度变化的生长和发育能力对于培育对预测温度变化具有弹性的植物品种至关重要。然而，植物对温度逐渐升高的反应机制才刚刚开始被阐明。在这里，我们报告说，细胞周期蛋白依赖性激酶 G1（CDKG1）是一个热敏感的 mRNA 剪接级联的核心元件，它将环境温度的变化转化为基本剪接体成分 ATU2AF65A 的差异表达。CDKG1 以温度依赖的方式进行可变剪接。我们发现，这个过程部分依赖于细胞周期蛋白依赖性激酶 G2（CDKG2）和相互作用的共因子细胞周期蛋白 L1（CYCL1），导致两种不同的信使 RNA。两种 CDKG1 转录本的相对丰度与环境温度相关，并且可能与相关蛋白异构体的不同表达水平相关。两种 CDKG1 替代转录本都需要在整个温度范围内完全补充 ATU2AF65A 的表达。我们的数据支持了一种以前未被识别的基于 CDKG1 的可变剪接（AS）的温度依赖性机制，该机制受 CDKG2 和 CYCL1 调控。我们提出，环境温度的变化会影响 CDKG1 转录本的相对丰度，进而转化为 CDKG1 蛋白表达的差异，从而协调 ATU2AF65A 的 AS。
