RRC ID 34851
Author Korekane H, Park JY, Matsumoto A, Nakajima K, Takamatsu S, Ohtsubo K, Miyamoto Y, Hanashima S, Kanekiyo K, Kitazume S, Yamaguchi Y, Matsuo I, Taniguchi N.
Title Identification of ectonucleotide pyrophosphatase/phosphodiesterase 3 (ENPP3) as a regulator of N-acetylglucosaminyltransferase GnT-IX (GnT-Vb).
Journal J. Biol. Chem.
Abstract Our previous studies on a β1,6-N-acetylglucosaminyltransferase, GnT-IX (GnT-Vb), a homolog of GnT-V, indicated that the enzyme has a broad GlcNAc transfer activity toward N-linked and O-mannosyl glycan core structures and that its brain-specific gene expression is regulated by epigenetic histone modifications. In this study, we demonstrate the existence of an endogenous inhibitory factor for GnT-IX that functions as a key regulator for GnT-IX enzymatic activity in Neuro2a (N2a) cells. We purified this factor from N2a cells and found that it is identical to ectonucleotide pyrophosphatase/phosphodiesterase 3 (ENPP3), as evidenced by mass spectrometry and by the knockdown and overexpression of ENPP3 in cultured cells. Kinetic analyses revealed that the mechanism responsible for the inhibition of GnT-IX caused by ENPP3 is the ENPP3-mediated hydrolysis of the nucleotide sugar donor substrate, UDP-GlcNAc, with the resulting generation of UMP, a potent and competitive inhibitor of GnT-IX. Indeed, ENPP3 knockdown cells had significantly increased levels of intracellular nucleotide sugars and displayed changes in the total cellular glycosylation profile. In addition to chaperones or other known regulators of glycosyltransferases, the ENPP3-mediated hydrolysis of nucleotide sugars would have widespread and significant impacts on glycosyltransferase activities and would be responsible for altering the total cellular glycosylation profile and modulating cellular functions.
Volume 288(39)
Pages 27912-26
Published 2013-9-27
DOI 10.1074/jbc.M113.474304
PII M113.474304
PMID 23960081
PMC PMC3784706
MeSH Animals COS Cells Carbohydrates / chemistry Cercopithecus aethiops Gene Expression Regulation, Enzymologic* Glycosylation Glycosyltransferases / metabolism HEK293 Cells Humans Hydrolysis Mice N-Acetylglucosaminyltransferases / metabolism* Nerve Tissue Proteins / metabolism* Nucleosides / chemistry Phosphoric Diester Hydrolases / metabolism* Plasmids / metabolism Pyrophosphatases / metabolism* RNA Interference
IF 4.106
Times Cited 11
DNA material pcDNA6.2/hGnT-IX(-LQ)-FLAG (RDB13427) pcDNA3.1/hGnT-V-myc-his (RDB13428) pcDNA3.1/mENPP3-myc-his (RDB13429) pcDNA3.1/mENPP3(T205A)-myc-his (RDB13430).