1. Academic Validation
  2. 7-Methylguanosine monophosphate analogues with 5'-(1,2,3-triazoyl) moiety: Synthesis and evaluation as the inhibitors of cNIIIB nucleotidase

7-Methylguanosine monophosphate analogues with 5'-(1,2,3-triazoyl) moiety: Synthesis and evaluation as the inhibitors of cNIIIB nucleotidase

  • Bioorg Med Chem. 2018 Jan 1;26(1):191-199. doi: 10.1016/j.bmc.2017.11.032.
Mateusz Kozarski 1 Dorota Kubacka 1 Blazej A Wojtczak 2 Renata Kasprzyk 3 Marek R Baranowski 1 Joanna Kowalska 4
Affiliations

Affiliations

  • 1 University of Warsaw, Faculty of Physics, Institute of Experimental Physics, Division of Biophysics, Pasteura 5, 02-093 Warsaw, Poland.
  • 2 University of Warsaw, Centre of New Technologies, Banacha 2c, 02-097 Warsaw, Poland.
  • 3 University of Warsaw, Centre of New Technologies, Banacha 2c, 02-097 Warsaw, Poland; University of Warsaw, College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, Banacha 2c, 02-097 Warsaw, Poland.
  • 4 University of Warsaw, Faculty of Physics, Institute of Experimental Physics, Division of Biophysics, Pasteura 5, 02-093 Warsaw, Poland. Electronic address: jkowalska@fuw.edu.pl.
Abstract

The hydrolysis of nucleoside 5'-monophosphates to the corresponding nucleosides and inorganic phosphate is catalysed by 5'-nucleotidases, thereby contributing to the control of endogenous nucleotide turnover and affecting the fate of exogenously delivered nucleotide- and nucleoside-derived therapeutics in cells. A recently identified nucleotidase cNIIIB shows preference towards 7-methylguanosine monophosphate (m7GMP) as a substrate, which suggests its potential involvement in mRNA degradation. However, the extent of biological functions and the significance of cNIIIB remains to be elucidated. Here, we synthesised a series of m7GMP analogues carrying a 1,2,3-triazole moiety at the 5' position as the potential inhibitors of human cNIIIB. The compounds were synthesised by using the copper-catalysed azide-alkyne cycloaddition (CuAAC) between 5'-azido-5'-deoxy-7-methylguanosine and different phosphate or phosphonate derivatives carrying terminal alkyne. The analogues were evaluated as cNIIIB inhibitors using HPLC and malachite green assays, demonstrating that compound 1a, carrying a 1,2,3-triazoylphosphonate moiety, inhibits cNIIIB activity at micromolar concentrations (IC50 87.8 ± 7.5 µM), while other analogues showed no activity. In addition, compound 1d was identified as an artifical substrate for HscNIIIB. Further characterization of inhibitor 1a revealed that it is poorly recognised by other m7G-binding proteins, eIF4E and DcpS, indicating its selectivity towards cNIIIB. The first inhibitor (1a) and unnatural substrate (1d) of cNIIIB, identified here, can be used as molecular probes for the elucidation of biological roles of cNIIIB, including the verification of its proposed function in mRNA metabolism.

Keywords

5′ Nucleotidase cNIIIB; 7-Methylguanosine 5′-monophosphate; Click chemistry; Enzyme inhibitor; mRNA cap; mRNA degradation.

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