Domingo Guido, Marsoni Milena, Chiodaroli Luca, Fortunato Stefania, Bracale Marcella, De Pinto Maria Concetta, Gehring Chris, Vannini Candida
Biotechnology and Life Science Department, University of Insubria, Varese, Italy.
KCS Biotech, Vergiate (VA), Italy.
Proteomics. 2023 Aug;23(15):e2300165. doi: 10.1002/pmic.202300165. Epub 2023 Jun 1.
3',5'-cyclic adenosine monophosphate (cAMP) is finally recognized as an essential signaling molecule in plants where cAMP-dependent processes include responses to hormones and environmental stimuli. To better understand the role of 3',5'-cAMP at the systems level, we have undertaken a phosphoproteomic analysis to elucidate the cAMP-dependent response of tobacco BY-2 cells. These cells overexpress a molecular "sponge" that buffers free intracellular cAMP level. The results show that, firstly, in vivo cAMP dampening profoundly affects the plant kinome and notably mitogen-activated protein kinases, receptor-like kinases, and calcium-dependent protein kinases, thereby modulating the cellular responses at the systems level. Secondly, buffering cAMP levels also affects mRNA processing through the modulation of the phosphorylation status of several RNA-binding proteins with roles in splicing, including many serine and arginine-rich proteins. Thirdly, cAMP-dependent phosphorylation targets appear to be conserved among plant species. Taken together, these findings are consistent with an ancient role of cAMP in mRNA processing and cellular programming and suggest that unperturbed cellular cAMP levels are essential for cellular homeostasis and signaling in plant cells.
3',5'-环磷酸腺苷（cAMP）最终被确认为植物中的一种重要信号分子，其中依赖cAMP的过程包括对激素和环境刺激的反应。为了在系统水平上更好地理解3',5'-cAMP的作用，我们进行了磷酸化蛋白质组分析，以阐明烟草BY-2细胞的cAMP依赖性反应。这些细胞过表达一种分子“海绵”，可缓冲细胞内游离cAMP水平。结果表明，首先，体内cAMP的抑制会深刻影响植物激酶组，特别是丝裂原活化蛋白激酶、类受体激酶和钙依赖性蛋白激酶，从而在系统水平上调节细胞反应。其次，缓冲cAMP水平还通过调节几种在剪接中起作用的RNA结合蛋白的磷酸化状态来影响mRNA加工，这些蛋白包括许多富含丝氨酸和精氨酸的蛋白。第三，cAMP依赖性磷酸化靶点在植物物种之间似乎是保守的。综上所述，这些发现与cAMP在mRNA加工和细胞编程中的古老作用一致，并表明不受干扰的细胞cAMP水平对于植物细胞的细胞稳态和信号传导至关重要。
