Edc4, also known as enhancer of mRNA-decapping protein 4, is a central scaffold component in cells. It plays a crucial role in the major cytoplasmic mRNA turnover pathway in eukaryotes, specifically in deadenylation-dependent mRNA decapping and decay. It interacts with key proteins like the decapping enzyme DCP2 and the 5'-3' exonuclease XRN1, and is also associated with processing bodies (P-bodies) which are involved in mRNA silencing, storage and decay [1,3]. Edc4 is also linked to other important cellular functions such as CoA biosynthesis regulation [4], DNA repair [5], and cell fate transitions through its role in P-body homeostasis [6,7].

Disrupting the EDC4-XRN1 interaction or altering their stoichiometry inhibits mRNA decapping, stabilizing microRNA-targeted mRNAs in a translationally repressed state and leading to 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]. Depletion of EDC4 in cancer cells can activate hallmarks of epithelial-mesenchymal transition (EMT), enhancing cell migration and metastasis, as P-bodies normally repress the translation of the EMT driver gene HMGA2 [7]. Also, EDC4 can both enhance mRNA turnover by binding DCP2 and repress MARF1-mediated mRNA decay by preventing MARF1 from binding target mRNAs [8].

In conclusion, Edc4 is essential for coordinating mRNA decapping with decay, maintaining P-body dynamics, and is involved in multiple biological processes. Its dysregulation is associated with diseases like Parkinson's and cancer. The study of Edc4 through genetic models has provided insights into its role in these biological processes and disease conditions, potentially guiding future therapeutic strategies.

References:

1. Brothers, William R, Ali, Farah, Kajjo, Sam, Fabian, Marc R. 2023. The EDC4-XRN1 interaction controls P-body dynamics to link mRNA decapping with decay. In The EMBO journal, 42, e113933. doi:10.15252/embj.2023113933. https://pubmed.ncbi.nlm.nih.gov/37621215/

2. Hallacli, Erinc, Kayatekin, Can, Nazeen, Sumaiya, Chung, Chee Yeun, Khurana, Vikram. . The Parkinson's disease protein alpha-synuclein is a modulator of processing bodies and mRNA stability. In Cell, 185, 2035-2056.e33. doi:10.1016/j.cell.2022.05.008. https://pubmed.ncbi.nlm.nih.gov/35688132/

3. Bloch, Donald B, Sinow, Claire O, Sauer, Andrew J, Corman, Benjamin H P. 2023. Assembly and regulation of the mammalian mRNA processing body. In PloS one, 18, e0282496. doi:10.1371/journal.pone.0282496. https://pubmed.ncbi.nlm.nih.gov/36877681/

4. Gudkova, Daria, Panasyuk, Ganna, Nemazanyy, Ivan, Filonenko, Valeriy, Gout, Ivan. 2012. EDC4 interacts with and regulates the dephospho-CoA kinase activity of CoA synthase. In FEBS letters, 586, 3590-5. doi:10.1016/j.febslet.2012.08.033. https://pubmed.ncbi.nlm.nih.gov/22982864/

5. Hernández, Gonzalo, Ramírez, María José, Minguillón, Jordi, Pujana, Miquel Àngel, Surrallés, Jordi. 2018. Decapping protein EDC4 regulates DNA repair and phenocopies BRCA1. In Nature communications, 9, 967. doi:10.1038/s41467-018-03433-3. https://pubmed.ncbi.nlm.nih.gov/29511213/

6. Di Stefano, Bruno, Luo, En-Ching, Haggerty, Chuck, Yeo, Gene W, Hochedlinger, Konrad. 2019. The RNA Helicase DDX6 Controls Cellular Plasticity by Modulating P-Body Homeostasis. In Cell stem cell, 25, 622-638.e13. doi:10.1016/j.stem.2019.08.018. https://pubmed.ncbi.nlm.nih.gov/31588046/

7. Fang, Liang, Zhang, Li, Wang, Mengran, Hu, Yuhui, Chen, Wei. . Pooled CRISPR Screening Identifies P-Bodies as Repressors of Cancer Epithelial-Mesenchymal Transition. In Cancer research, 84, 659-674. doi:10.1158/0008-5472.CAN-23-1693. https://pubmed.ncbi.nlm.nih.gov/38190710/

8. Brothers, William R, Hebert, Steven, Kleinman, Claudia L, Fabian, Marc R. 2020. A non-canonical role for the EDC4 decapping factor in regulating MARF1-mediated mRNA decay. In eLife, 9, . doi:10.7554/eLife.54995. https://pubmed.ncbi.nlm.nih.gov/32510323/