Effect of different N7 substitution of dinucleotide cap analogs on the hydrolytic susceptibility towards scavenger decapping enzymes (DcpS)

• Published in: Biochemical and biophysical research communications 2015-08, Vol.464 (1), p.89-93
• Main Authors: Piecyk, Karolina, Darzynkiewicz, Zbigniew M., Jankowska-Anyszka, Marzena, Ferenc-Mrozek, Aleksandra, Stepinski, Janusz, Darzynkiewicz, Edward, Bojarska, Elzbieta
• Format: Article
• Language: English
• Subjects: Animals; Ascaris suum - genetics; Ascaris suum - metabolism; Caenorhabditis elegans - genetics; Caenorhabditis elegans - metabolism; Caenorhabditis elegans Proteins - chemistry; Caenorhabditis elegans Proteins - genetics; Caenorhabditis elegans Proteins - metabolism; Cap analogs; Decapping scavengers; Endoribonucleases - chemistry; Endoribonucleases - genetics; Endoribonucleases - metabolism; Enzyme Assays; Enzyme kinetic; Escherichia coli - genetics; Escherichia coli - metabolism; Fluorescence titration; Gene Expression; Humans; Isoenzymes - chemistry; Isoenzymes - genetics; Isoenzymes - metabolism; Kinetics; mRNA degradation; Nucleic Acid Conformation; Pyrophosphatases - chemistry; Pyrophosphatases - genetics; Pyrophosphatases - metabolism; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; RNA Cap Analogs - chemistry; RNA Cap Analogs - metabolism; RNA Stability - genetics; Static Electricity
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2015.06.001

Scavenger decapping enzymes (DcpS) are involved in eukaryotic mRNA degradation process. They catalyze the cleavage of residual cap structure m7GpppN and/or short capped oligonucleotides resulting from exosom–mediated the 3′ to 5′ digestion. For the specific cap recognition and efficient degradation by DcpS, the positive charge at N7 position of guanine moiety is required. Here we examine the role the N7 substitution within the cap structure on the interactions with DcpS (human, Caenorhabditis elegans and Ascaris suum) comparing the hydrolysis rates of dinucleotide cap analogs (m7GpppG, et7GpppG, but7GpppG, bn7GpppG) and the binding affinities of hydrolysis products (m7GMP, et7GMP, but7GMP, bn7GMP). Our results show the conformational flexibility of the region within DcpS cap-binding pocket involved in the interaction with N7 substituted guanine, which enables accommodation of substrates with differently sized N7 substituents. •N7 substituent in cap analogs influences their hydrolytic susceptibility towards DcpS.•Conformational flexibility of DcpS cap-binding pocket enables substrate accommodation.•Week binding of hydrolysis products affects cap degradation by DcpS.