Decapping metalloenzyme that catalyzes the cleavage of the cap structure on mRNAs (PubMed:16199859). Removes the 7-methyl guanine cap structure from mRNA molecules, yielding a 5'-phosphorylated mRNA fragment and 7m-GDP (PubMed:16199859). RNA-decapping enzyme although it does not bind the RNA cap (PubMed:16199859). May contribute to gene regulation in multiple RNA pathways including monomethylguanosine- and trimethylguanosine-capped RNAs (PubMed:16199859). In oocytes, may play a role in the response to stress induced by heat shock, osmotic stress and anoxia (PubMed:18439994). Required for the developmental axon guidance and regrowth of PLM touch receptor neurons (PubMed:31983639). Early in embryogenesis, plays a role in ciliary shape formation in sensory neurons (PubMed:28887031). Promotes survival at high temperatures (PubMed:25061667). a 5'-end (N(7)-methyl 5'-triphosphoguanosine)-ribonucleoside in mRNA + H2O = a 5'-end phospho-ribonucleoside in mRNA + 2 H(+) + N(7)-methyl-GDP a 5'-end (N(2),N(2),N(7)-trimethyl 5'-triphosphoguanosine)-(ribonucleoside) in mRNA + H2O = a 5'-end phospho-ribonucleoside in mRNA + 2 H(+) + N(2),N(2),N(7)-trimethyl-GDP Inhibited by capped and uncapped RNA (PubMed:16199859). Not inhibited by dinucleotide cap or methylated nucleotide analogs (PubMed:16199859). May be a component of the decapping complex composed of dcap-1 and dcap-2. Localizes to perinuclear puncta in pachytene-stage germ cells (PubMed:18439994). Diffusely localized to cytoplasmic puncta in maturing oocytes (PubMed:18439994). Expressed in sensory neurons. Double RNAi-mediated knockdown with dcap-1 reduces survival at 20 degrees Celsius. Belongs to the Nudix hydrolase family. DCP2 subfamily. Truncated N-terminus.