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O‐GlcNAcomic profiling reveals altered O‐GlcNAcylation of mitochondrial proteins in diabetes (608.4)
Author(s) -
Ma Junfeng,
Liu Ting,
Wei AnChi,
O'Rourke Brian,
Hart Gerald
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.608.4
Subject(s) - dithiothreitol , oxidative phosphorylation , diabetic cardiomyopathy , mitochondrion , biochemistry , metabolism , chemistry , western blot , biology , medicine , cardiomyopathy , gene , enzyme , heart failure
As a dynamically regulated post‐translational modification, O‐linked β‐D‐N‐acetylglucosamine addition (O‐GlcNAcylation) plays critical roles in various physiological events [1]. Aberrant O‐GlcNAcylation is involved in numerous diseases including diabetes and diabetic complications [2]. However, mitochondrial O‐GlcNAc proteins have far from being well characterized and their functions are largely unknown. To this end, a refined β‐Elimination followed by Michael Addition with Dithiothreitol approach was combined with reversed phase liquid chromatography (RPLC) fractionation followed by tandem mass spectrometry, yielding dozens of O‐GlcNAcylated proteins from cardiac mitochondria. The identified O‐GlcNAc proteins are involved not only in energy metabolism (i.e., oxidative phosphorylation, the Krebs cycle, and beta‐oxidation) but also in many other processes (e.g., heme biosynthesis, and amino acid metabolism). Moreover, by incorporating isotopic dithiothreitol reagents, the relative site‐specific O‐GlcNAc occupancy was also uncovered in control and diabetic hearts. Of note, multiple respiratory chain proteins have been found differentially O‐GlcNAcylated, as confirmed by western blots with O‐GlcNAc‐specific antibodies. Moreover, the O‐GlcNAcylation of respiratory chain proteins appears to be closely related to the alteration of mitochondrial dysfunctions including respiratory rate and production of reactive oxygen species. These results suggest that mitochondrial protein O‐GlcNAcylation underlies the etiology and progression of diabetic cardiomyopathy, providing a novel insight and, more importantly, new treatments to diabetes. Grant Funding Source : Supported by NIH R01CA42486, R01DK61671, N01‐HV‐00240, P01HL107153.