Extensive crosstalk between O-GlcNAcylation and phosphorylation regulates cytokinesis

• Published in: Science signaling 2010-01, Vol.3 (104), p.ra2-ra2
• Main Authors: Wang, Zihao, Udeshi, Namrata D, Slawson, Chad, Compton, Philip D, Sakabe, Kaoru, Cheung, Win D, Shabanowitz, Jeffrey, Hunt, Donald F, Hart, Gerald W
• Format: Article
• Language: English
• Subjects: Acetylglucosamine - metabolism; Amino Acid Sequence; Antigens, Nuclear - metabolism; Binding Sites - genetics; Blotting, Western; CDC2 Protein Kinase - genetics; CDC2 Protein Kinase - metabolism; Centrosome - metabolism; Cytokinesis - genetics; Cytokinesis - physiology; Glycosylation; HeLa Cells; Humans; Models, Biological; Molecular Sequence Data; N-Acetylglucosaminyltransferases - genetics; N-Acetylglucosaminyltransferases - metabolism; Neoplasm Proteins - metabolism; Nuclear Matrix-Associated Proteins - metabolism; Nuclear Pore Complex Proteins - metabolism; Nuclear Proteins - metabolism; Phosphorylation; Protein Binding; Proteomics; Repressor Proteins - metabolism; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Spindle Apparatus - metabolism
• ISSN: 1945-0877; 1937-9145
• DOI: 10.1126/scisignal.2000526

Like phosphorylation, the addition of O-linked beta-N-acetylglucosamine (O-GlcNAcylation) is a ubiquitous, reversible process that modifies serine and threonine residues on nuclear and cytoplasmic proteins. Overexpression of the enzyme that adds O-GlcNAc to target proteins, O-GlcNAc transferase (OGT), perturbs cytokinesis and promotes polyploidy, but the molecular targets of OGT that are important for its cell cycle functions are unknown. Here, we identify 141 previously unknown O-GlcNAc sites on proteins that function in spindle assembly and cytokinesis. Many of these O-GlcNAcylation sites are either identical to known phosphorylation sites or in close proximity to them. Furthermore, we found that O-GlcNAcylation altered the phosphorylation of key proteins associated with the mitotic spindle and midbody. Forced overexpression of OGT increased the inhibitory phosphorylation of cyclin-dependent kinase 1 (CDK1) and reduced the phosphorylation of CDK1 target proteins. The increased phosphorylation of CDK1 is explained by increased activation of its upstream kinase, MYT1, and by a concomitant reduction in the transcript for the CDK1 phosphatase, CDC25C. OGT overexpression also caused a reduction in both messenger RNA expression and protein abundance of Polo-like kinase 1, which is upstream of both MYT1 and CDC25C. The data not only illustrate the crosstalk between O-GlcNAcylation and phosphorylation of proteins that are regulators of crucial signaling pathways but also uncover a mechanism for the role of O-GlcNAcylation in regulation of cell division.