Edc4, known as enhancer of mRNA-decapping protein 4, is a key scaffold component in mRNA metabolism. It is involved in the deadenylation-dependent mRNA decapping and decay pathway, a major cytoplasmic mRNA turnover mechanism in eukaryotes [1]. It interacts with proteins like the decapping enzyme DCP2 and the 5'-3' exonuclease XRN1, and is also associated with processing bodies (P-bodies), which are ribonucleoprotein granules related to mRNA decay and storage [1,2,3].

Disrupting the EDC4-XRN1 interaction or altering their stoichiometry inhibits mRNA decapping, leading to the stabilization of microRNA-targeted mRNAs in a translationally repressed state. This also results in larger P-bodies that prevent mRNA decapping [1]. In Parkinson's disease, pathological accumulation of α-synuclein leads to aberrant interaction with Edc4, disrupting mRNA decay kinetics in relevant pathways [2]. Silencing EDC4 can activate hallmarks of epithelial-mesenchymal transition (EMT) in cancer cells, enhancing cell migration and metastasis, as P-bodies can repress the translation of the EMT driver gene HMGA2 [4]. EDC4 also interacts with CoA synthase, regulating its dephospho-CoA kinase activity [5]. Additionally, EDC4 is part of the BRCA1-BRIP1-TOPBP1 complex, playing a role in homologous recombination for DNA repair, and its deficiency leads to genome instability and hypersensitivity to certain drugs [6].

In summary, Edc4 has diverse functions in mRNA metabolism, P-body regulation, and DNA repair. Its disruption is associated with diseases like Parkinson's disease and cancer, highlighting its importance in understanding disease mechanisms. Studies on Edc4, especially through loss-of-function models, contribute to revealing its role in these biological processes and disease conditions.