title: hNUDT16: a universal decapping enzyme for small nucleolar RNA and cytoplasmic mRNA.
abstract: Human NUDT16 (hNUDT16) is a decapping enzyme initially identified as the human homolog to the Xenopus laevis X29. As a metalloenzyme, hNUDT16 relies on divalent cations for its cap-hydrolysis activity to remove m⁷GDP and m²²⁷GDP from RNAs. Metal also determines substrate specificity of the enzyme. So far, only U8 small nucleolar RNA (snoRNA) has been identified as the substrate of hNUDT16 in the presence of Mg²(+). Here we demonstrate that besides U8, hNUDT16 can also actively cleave the m⁷GDP cap from mRNAs in the presence of Mg²(+) or Mn²(+). We further show that hNUDT16 does not preferentially recognize U8 or mRNA substrates by our cross-inhibition and quantitative decapping assays. In addition, our mutagenesis analysis identifies several key residues involved in hydrolysis and confirms the key role of the REXXEE motif in catalysis. Finally an investigation into the subcellular localization of hNUDT16 revealed its abundance in both cytoplasm and nucleus. These findings extend the substrate spectrum of hNUDT16 beyond snoRNAs to also include mRNA, demonstrating the pleiotropic decapping activity of hNUDT16.
authors.affiliation: CAS Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, 100101, China.
authors.forename: Guangwen
authors.initials: G
authors.lastname: Lu
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Zhixin
authors.initials: Z
authors.lastname: Li
authors.forename: Na
authors.initials: N
authors.lastname: Zhang
authors.forename: Xiang
authors.initials: X
authors.lastname: Xu
authors.forename: Tingting
authors.initials: T
authors.lastname: Wang
authors.forename: Zhenhong
authors.initials: Z
authors.lastname: Guan
authors.forename: George F
authors.initials: GF
authors.lastname: Gao
authors.forename: Jinghua
authors.initials: J
authors.lastname: Yan
mesh_terms: D020816:Amino Acid Motifs; D055162:Biocatalysis; D002467:Cell Nucleus / Q000201:enzymology; D016384:Consensus Sequence; D003593:Cytoplasm / Q000201:enzymology / Q000378:metabolism*; D006153:Guanosine Diphosphate / Q000378:metabolism; D006639:Histidine / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D008156:Luciferases / Q000235:genetics; D008274:Magnesium / Q000378:metabolism; D008345:Manganese / Q000378:metabolism; D016296:Mutagenesis; D009154:Mutation; D011755:Pyrophosphatases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012315:RNA Caps / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D020537:RNA, Small Nucleolar / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D012315:RNA Caps; D020537:RNA, Small Nucleolar; D006153:Guanosine Diphosphate; D008345:Manganese; D006639:Histidine; D008156:Luciferases; C523314:Nudt16 protein, human; D011755:Pyrophosphatases; D008274:Magnesium