Dcp2, the major mRNA decapping enzyme in eukaryotic cells, plays a crucial role in regulating cellular mRNA levels. Eukaryotic mRNAs have a 5' cap structure that protects against exonucleolytic degradation, and Dcp2-through interactions with activators like Dcp1, Edc1, and Edc3, as well as an autoinhibition mechanism-controls the mRNA decapping pathways [1]. This process is vital for numerous biological functions such as the tight control of LINE-1 mobilization in maintaining genetic stability [2], and the regulation of chemoresistance in small cell lung cancer [3], and neuronal apoptosis in chronic cerebral ischemia [4].

In yeast, genetic analyses have shown that Dcp2 C-terminal domain cis-regulatory elements control decapping enzyme target specificity by forming distinct decapping complexes, with Upf1, Edc3, Scd6, and Pat1 acting as regulatory subunits controlling substrate specificity and enzymatic activation [5]. RNA-Seq and ribosome profiling in dcp2Δ yeast cells revealed that Dcp2 affects mRNA abundance and translation, adjusting metabolism and filamentation according to nutrient availability [6]. In mammalian cells, reduced Dcp2 levels led to increased mRNA and protein levels of key type I IFN transcription factor IRF-7, suggesting Dcp2 modulates IRF-7 mRNA stability and may negatively contribute to the innate immune response in a negative feedback mechanism [7].

In conclusion, Dcp2 is essential for regulating mRNA stability and translation, influencing various biological processes and disease-related pathways. Studies using gene-knockout models in yeast and reduced-expression models in mammalian cells have provided insights into its role in processes like genetic stability maintenance, chemoresistance, neuronal apoptosis, and the innate immune response.