Edc3

Edc3, or Enhancer of Decapping 3, is a conserved RNA-binding protein that participates in the 5' to 3' mRNA decay pathway. In budding yeast and many other eukaryotes, Edc3 acts as a decapping activator that promotes removal of the 5' cap by the Dcp1–Dcp2 catalytic complex, facilitating transcript turnover.

Edc3 functions by binding to decapping factors and to target mRNAs, helping recruit Dcp1–Dcp2 and other decay factors to transcripts marked for decay. It also contributes to the assembly and maintenance of cytoplasmic processing bodies (P-bodies), dynamic foci that accumulate decapping factors and untranslated mRNAs when translation is repressed or stress occurs.

Structural and sequence features of Edc3 vary by species. In many organisms, Edc3 proteins contain motifs for protein–protein interactions and regions rich in low-complexity sequences that support associations with other decapping factors and may promote phase separation into P-bodies. The C-terminal region often plays a role in P-body targeting and multimerization.

Evolutionarily, Edc3 is broadly conserved among eukaryotes, with orthologs in fungi and other lineages. Its role in mRNA decay can overlap with other decapping activators such as Edc1 and Edc2, and functional studies in yeast and other models have shown that loss of Edc3 affects mRNA stability and P-body dynamics.

See also mRNA decay, decapping, Dcp1, Dcp2, P-bodies.