title: Biochemical characterization of the M712T-mutation of the UDP-N-acetylglucosamine 2-epimerase/N-acetyl-mannosaminekinase in hereditary inclusion body myopathy.
abstract: Hereditary inclusion body myopathy is a neuromuscular disorder characterized by muscle weakness with a late onset and slow progression. It is caused by mutations of the gene encoding UDP-N-acetylglucosamine-2-epimerase/N-acetylmannosamine kinase (GNE). One of the most frequent mutations is an exchange of methionine to threonine at position 712 (M712T). Here we analyzed wildtype (wt) and M712T-mutated (M712T) GNE. We identified threonine 712 as an additional possible phosphorylation site and found by two-dimensional gel-electrophoresis a lower isoelectric point compared to wt-GNE. This lower isoelectric point could be partially reversed back to the wildtype isoelectric point after treatment with protein phosphatase. Furthermore, in contrast to wt-GNE, a significant fraction of M712T-GNE was in the insoluble fraction. Finally, by using bimolecular fluorescence complementation we demonstrate that the M712T mutation does not disrupt the formation of GNE-oligomers.
authors.affiliation: Institute of Physiological Chemistry, Martin-Luther University of Halle-Wittenberg, Hollystr. 1, D-06114 Halle, Germany.
authors.forename: Wenke
authors.initials: W
authors.lastname: Weidemann
authors.forename: Anika
authors.initials: A
authors.lastname: Reinhardt
authors.forename: Annett
authors.initials: A
authors.lastname: Thate
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Horstkorte
mesh_terms: D000818:Animals; D016466:CHO Cells; D002478:Cells, Cultured; D006224:Cricetinae; D004252:DNA Mutational Analysis; D006367:HeLa Cells; D006801:Humans; D002479:Inclusion Bodies / Q000235:genetics / Q000378:metabolism; D007526:Isoelectric Point; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D009135:Muscular Diseases / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D017354:Point Mutation; D051381:Rats
chemical_list: D009097:Multienzyme Complexes; C482901:UDP-N-acetylglucosamine 2-epimerase - N-acetylmannosamine kinase