A mitotic GlcNAcylation/phosphorylation signaling complex alters the posttranslational state of the cytoskeletal protein vimentin

Mol Biol Cell. 2008 Oct;19(10):4130-40. doi: 10.1091/mbc.e07-11-1146. Epub 2008 Jul 23.

Abstract

O-linked beta-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.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Acetylglucosamine / metabolism*
  • Aurora Kinase B
  • Aurora Kinases
  • Cell Division
  • Cytokinesis
  • HeLa Cells
  • Humans
  • Microscopy, Confocal
  • Miosis
  • Mitosis*
  • Models, Biological
  • N-Acetylglucosaminyltransferases / metabolism*
  • Phosphorylation
  • Protein Processing, Post-Translational*
  • Protein Serine-Threonine Kinases / metabolism
  • Signal Transduction
  • Vimentin / metabolism*

Substances

  • Vimentin
  • N-Acetylglucosaminyltransferases
  • O-GlcNAc transferase
  • AURKB protein, human
  • Aurora Kinase B
  • Aurora Kinases
  • Protein Serine-Threonine Kinases
  • Acetylglucosamine