Slawson, Chad*, T. Lakshmanan, Spencer Knapp, and Gerald W. Hart*, 2008, Mol. Biol. Cell:19: 4130-4140
*Department of Biological Chemistry, The Johns Hopkins School of Medicine, Baltimore, MD 21205; Momenta Pharmaceuticals, Cambridge, MA 02142; and Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08554
O-linked β-N-acetylglucosamine (O-GlcNAc) is a highly dynamic intracellular protein modification responsive to stress, hormones, nutrients, and cell cycle stage. Alterations in O-GlcNAc addition or removal (cycling) impair cell cycle progression and cytokinesis, but the mechanisms are not well understood. Here, we demonstrate that the enzymes responsible for O-GlcNAc cycling, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) are in a transient complex at M phase with the mitotic kinase Aurora B and protein phosphatase 1. OGT colocalized to the midbody during telophase with Aurora B. Furthermore, these proteins coprecipitated with each other in a late mitotic extract. The complex was stable under Aurora inhibition; however, the total cellular levels of O-GlcNAc were increased and the localization of OGT was decreased at the midbody after Aurora inhibition. Vimentin, an intermediate filament protein, is an M phase substrate for both Aurora B and OGT. Overexpression of OGT or OGA led to defects in mitotic phosphorylation on multiple sites, whereas OGT overexpression increased mitotic GlcNAcylation of vimentin. OGA inhibition caused a decrease in vimentin late mitotic phosphorylation but increased GlcNAcylation. Together, these data demonstrate that the O-GlcNAc cycling enzymes associate with kinases and phosphatases at M phase to regulate the posttranslational status of vimentin.
*Note: The Donkey anti-IgY agarose used in this publication were produced by Gallus Immunotech Inc. Please see the Product Specifications for more information.