Decapping complex

The mRNA decapping complex is a protein complex in eukaryotic cells responsible for removal of the 5' cap. The active enzyme of the decapping complex is the bilobed Nudix family enzyme Dcp2, which hydrolyzes 5' cap and releases 7mGDP and a 5'-monophosphorylated mRNA. This decapped mRNA is inhibited for translation and will be degraded by exonucleases. The core decapping complex is conserved in eukaryotes. Dcp2 is activated by Decapping Protein 1 (Dcp1) and in higher eukaryotes joined by the scaffold protein VCS. Together with many other accessory proteins, the decapping complex assembles in P-bodies in the cytoplasm.

The mRNA decapping complex is a protein complex in eukaryotic cells responsible for removal of the 5' cap. The active enzyme of the decapping complex is the bilobed Nudix family enzyme Dcp2, which hydrolyzes 5' cap and releases 7mGDP and a 5'-monophosphorylated mRNA. This decapped mRNA is inhibited for translation and will be degraded by exonucleases. The core decapping complex is conserved in eukaryotes. Dcp2 is activated by Decapping Protein 1 (Dcp1) and in higher eukaryotes joined by the scaffold protein VCS. Together with many other accessory proteins, the decapping complex assembles in P-bodies in the cytoplasm. ===Yeast decapping complex=== In yeast (S. cerevisiae), Dcp2 is joined by the decapping activator Dcp1, the helicase Dhh1, the exonuclease Xrn1, nonsense mediated decay factors Upf1, Upf2, and Upf3, the LSm complex, Pat1, and various other proteins. These proteins all localize to cytoplasmic structures called P-bodies. Notably in yeast there are no translation factors or ribosomal proteins inside P-bodies. ===Metazoan decapping complex=== Higher eukaryotes have slightly different members of the decapping complex. The enzyme Dcp2 is still the catalytic subunit which forms a holoenzyme with Dcp1, and interacts with auxiliary proteins such as Xrn1, Upf1, Upf2, Upf3, the LSm complex, and the Dhh1 ortholog DDX6. Proteins unique to plants and mammals include the beta propeller protein Hedls and the enhancer of decapping Edc3. Researchers know how the complex physically associates because of immunoprecipitation, while structural details of each part of the complex have been discovered by using x-ray crystallography in conjunction with protein crystallization. Each of these proteins contribute different things to the decapping complex, as discussed below.

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