Polo-like kinase 1 (PLK1) O-GlcNAcylation is essential for dividing mammalian cells and inhibits uterine carcinoma

• Published in: The Journal of biological chemistry 2023-02, Vol.299 (2), p.102887, Article 102887
• Main Authors: Yan, Sheng, Peng, Bin, Kan, Shifeng, Shao, Guangcan, Xiahou, Zhikai, Tang, Xiangyan, Chen, Yong-Xiang, Dong, Meng-Qiu, Liu, Xiao, Xu, Xingzhi, Li, Jing
• Format: Article
• Language: English
• Subjects: Acylation; Animals; Cell Division - physiology; Female; Humans; Mice; Mitosis; Mutation; O-GlcNAc; PLK1; Polo-Like Kinase 1; Protein Serine-Threonine Kinases - genetics; Protein Serine-Threonine Kinases - metabolism; Proto-Oncogene Proteins - genetics; Ubiquitination; Uterine carcinoma; Uterine Neoplasms - enzymology; Uterine Neoplasms - genetics
• ISSN: 0021-9258; 1083-351X; 1083-351X
• DOI: 10.1016/j.jbc.2023.102887

The O-linked β-N-acetylglucosamine (O-GlcNAc) transferase (OGT) mediates intracellular O-GlcNAcylation modification. O-GlcNAcylation occurs on Ser/Thr residues and is important for numerous physiological processes. OGT is essential for dividing mammalian cells and is involved in many human diseases; however, many of its fundamental substrates during cell division remain unknown. Here, we focus on the effect of OGT on polo-like kinase 1 (PLK1), a mitotic master kinase that governs DNA replication, mitotic entry, chromosome segregation, and mitotic exit. We show that PLK1 interacts with OGT and is O-GlcNAcylated. By utilizing stepped collisional energy/higher-energy collisional dissociation mass spectrometry, we found a peptide fragment of PLK1 that is modified by O-GlcNAc. Further mutation analysis of PLK1 shows that the T291A mutant decreases O-GlcNAcylation. Interestingly, T291N is a uterine carcinoma mutant in The Cancer Genome Atlas. Our biochemical assays demonstrate that T291A and T291N both increase PLK1 stability. Using stable H2B-GFP cells, we found that PLK1-T291A and PLK1-T291N mutants display chromosome segregation defects and result in misaligned and lagging chromosomes. In mouse xenograft models, we demonstrate that the O-GlcNAc–deficient PLK1-T291A and PLK1-T291N mutants enhance uterine carcinoma in animals. Hence, we propose that OGT partially exerts its mitotic function through O-GlcNAcylation of PLK1, which might be one mechanism by which elevated levels of O-GlcNAc promote tumorigenesis.