TOPK and PTEN participate in CHFR mediated mitotic checkpoint

• Published in: Cellular signalling 2013-12, Vol.25 (12), p.2511-2517
• Main Authors: Shinde, Swapnil R., Gangula, Narmadha Reddy, Kavela, Sridhar, Pandey, Vimal, Maddika, Subbareddy
• Format: Article
• Language: English
• Subjects: Akt; Cell Cycle Proteins - metabolism; Chfr; E3 ligase; HeLa Cells; Humans; Kinases; Lipids; M Phase Cell Cycle Checkpoints; Maintenance; Mitogen-Activated Protein Kinase Kinases - metabolism; Mitosis; Neoplasm Proteins - metabolism; Phosphorylation; Players; Poly-ADP-Ribose Binding Proteins; Progressions; Proteins; Proto-Oncogene Proteins c-akt - metabolism; PTEN; PTEN Phosphohydrolase - metabolism; Stability; TOPK; Ubiquitin - metabolism; Ubiquitin-Protein Ligases; Ubiquitination
• ISSN: 0898-6568; 1873-3913
• DOI: 10.1016/j.cellsig.2013.08.013

Mitotic progression is regulated by co-ordinated action of several proteins and is crucial for the maintenance of genomic stability. CHFR (Check point protein with FHA and RING domains) is an E3 ubiquitin ligase and a checkpoint protein that regulates entry into mitosis. But the molecular players involved in CHFR mediated mitotic checkpoint are not completely understood. In this study, we identified TOPK/PBK, a serine/threonine kinase and PTEN, a lipid phosphatase to play an important role in CHFR mediated mitotic transitions. We demonstrated that CHFR ubiquitinates and regulates TOPK levels, which is essential for its checkpoint function. Moreover, TOPK phosphorylates and inactivates PTEN, which in turn activates Akt that leads to proper G2/M progression. Collectively, our results reveal TOPK and PTEN as new players in CHFR mediated mitotic checkpoint. •TOPK is identified as a novel CHFR associated protein.•TOPK is a substrate of CHFR.•TOPK participates in CHFR mediated mitotic stress check point.•PTEN is phosphorylated by TOPK and is required for mitotic entry.