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 m7 GDP and...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 m7 GDP 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 m7 GDP 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.展开更多
The objective of the study was to establish the effect of formic acid on varroa(Varroa destructor),inside the capped brood cells,artificially decapped.The experiments were carried out in 2017-2018 on honeybee colonies...The objective of the study was to establish the effect of formic acid on varroa(Varroa destructor),inside the capped brood cells,artificially decapped.The experiments were carried out in 2017-2018 on honeybee colonies infested with varroa(V.destructor),in a research apiary belonging to the Institute for Beekeeping Research and Development in Bucharest.The decapping method in the present researches used the decapping fork to scrape the capped comb,without affecting the brood,in order to open it for an effective treatment.The combined treatment method was applied on honeybee colonies as a whole,as well as on brood combs,without bees,put in a special treatment box.The researches were focused on establishing the mortality level of various stages of varroa in artificially decapped brood,in normal colony and separately,as well as to make observations on the effect of formic acid on viability of capped bee brood,artificially decapped.The results show a high mortality of varroa,especially the protonymphs and deutonymphs stages(over 80%).The main conclusion is that the brood decapping method combined with formic acid treatment could be a useful technique to control varroa infestation,both in brood and honeybees,shortening strongly the treatment duration as compared to the usual treatments,increasing the efficacy of treatment by cutting the life cycle of varroa in brood.展开更多
基金the Natural Science Foundation of China(No.30870118)。
文摘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 m7 GDP 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 m7 GDP 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.
文摘The objective of the study was to establish the effect of formic acid on varroa(Varroa destructor),inside the capped brood cells,artificially decapped.The experiments were carried out in 2017-2018 on honeybee colonies infested with varroa(V.destructor),in a research apiary belonging to the Institute for Beekeeping Research and Development in Bucharest.The decapping method in the present researches used the decapping fork to scrape the capped comb,without affecting the brood,in order to open it for an effective treatment.The combined treatment method was applied on honeybee colonies as a whole,as well as on brood combs,without bees,put in a special treatment box.The researches were focused on establishing the mortality level of various stages of varroa in artificially decapped brood,in normal colony and separately,as well as to make observations on the effect of formic acid on viability of capped bee brood,artificially decapped.The results show a high mortality of varroa,especially the protonymphs and deutonymphs stages(over 80%).The main conclusion is that the brood decapping method combined with formic acid treatment could be a useful technique to control varroa infestation,both in brood and honeybees,shortening strongly the treatment duration as compared to the usual treatments,increasing the efficacy of treatment by cutting the life cycle of varroa in brood.
