Dcp1Dcp2

Dcp1Dcp2 is the core eukaryotic mRNA decapping complex, formed by the catalytic RNA hydrolase Dcp2 and the regulatory subunit Dcp1. The complex removes the 5' cap structure, a 7-methylguanosine (m7G) cap attached to most mRNAs, thereby converting the transcript into a form that is rapidly degraded by the 5' to 3' exonuclease Xrn1. This decapping step is a central control point in mRNA turnover and gene expression.

Dcp2 contains the Nudix hydrolase domain responsible for catalysis, while Dcp1 enhances activity and mediates interactions with other decapping cofactors. The two proteins form a stable heterodimer in many eukaryotes, and orthologs of Dcp1 and Dcp2 are found from yeast to humans, often with multiple isoforms in higher organisms. The activity of the complex is modulated by accessory factors and cellular context, and is frequently coordinated with translational repression and subcellular localization to processing bodies (P-bodies) in the cytoplasm.

In yeast and animals, several cofactors promote decapping by recruiting Dcp1–Dcp2 to specific mRNA substrates or by stimulating the catalytic step; examples include Edc proteins, Pat1, and Lsm1-7 complexes. Stress, development, and signaling can influence P-body assembly and decapping rates.

Functionally, Dcp1–Dcp2-mediated decapping commits mRNA to 5'–3' decay and contributes to quality control pathways such as nonsense-mediated decay. Failures in regulation or components can alter transcript stability and gene expression patterns. The Dcp1–Dcp2 complex was first characterized in yeast and is now recognized as a conserved core of eukaryotic mRNA decay.