EDC-3 and EDC-4 Regulate Embryonic mRNA Clearance and Biomolecular Condensate Specialization
Animal development is dictated by the selective and timely decay of mRNAs in developmental transitions, but the impact of mRNA decapping scaffold proteins in development is unknown. This study unveils the roles and interactions of the DCAP-2 decapping scaffolds EDC-3 and EDC-4 in the embryonic development of C. elegans. EDC-3 facilitates the timely removal of specific embryonic mRNAs, including cgh-1, car-1, and ifet-1 by reducing their expression, and preventing excessive accumulation of DCAP-2 condensates in somatic cells. We further uncover a novel role for EDC-3 in defining the boundaries between P-bodies, germ granules, and stress granules. Lastly, we show that EDC-4 counteracts EDC-3 and engenders the assembly of DCAP-2 with the GID (CTLH) complex, a ubiquitin ligase involved in maternal-to-zygotic transition (MZT). Our findings support a model wherein multiple RNA decay mechanisms temporally partake in the clearance of maternal and zygotic mRNAs throughout embryonic development. Overall design: To investigate the transcriptome-wide effect of EDC-3 and EDC-4, we performed RNA-seq on 4 biological replicates of RNA extracted from mixed-stage C. elegans embryos of WT (N2 strain), edc-3(ok1427) (RB1311 strain), edc-4(qe49) (FD135 strain), and edc-3(ok1427); edc-4(qe49) (FD135 strain). Differential gene expression and GSEA analyses were done to determine the differentially expressed genes and biological pathways in the mutants compared to WT.