Ubiquitin-mediated proteolysis is the key to cell cycle control. Anaphase-promoting complex/cyclosome (APC) is a ubiquitin ligase that targets cyclin B and factors regulating sister chromatid separation for proteolysis by the proteasome and, consequently, regulates metaphase-anaphase transition and exit from mitosis. Here we report that Cdc2-cyclin B-activated Polo-like kinase (Plk) specifically phosphorylates at least three components of APC and activates APC to ubiquitinate cyclin B in the in vitro-reconstituted system. Conversely, protein kinase A (PKA) phosphorylates two subunits of APC but suppresses APC activity. PKA is superior to Plk in its regulation of APC, and Plk activity peaks whereas PKA activity is falling at metaphase. These results indicate that Plk and PKA regulate mitosis progression by controlling APC activity.
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http://dx.doi.org/10.1016/s1097-2765(00)80037-4 | DOI Listing |
Cancer Sci
January 2025
Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
Effective therapeutic strategies for epithelioid sarcoma (EpS), a high-grade soft tissue sarcoma characterized by loss of integrase interactor 1 (INI1), have not yet been developed. The present study therefore investigated the association between INI1 loss and upregulation of the aurora kinase A (AURKA)/polo-like kinase 1 (PLK1)/cell division cycle 25C (CDC25C) axis, as well as the therapeutic relevance of this axis in EpS. Notably, our findings showed that the reintroduction of INI1 in VA-ES-BJ cells significantly reduced proliferation, mitigated tumorigenicity, and negatively regulated the expression of AURKA and its downstream effectors, as well as the activation of PLK1 and CDC25C.
View Article and Find Full Text PDFAm J Hypertens
January 2025
Department of Cardiology, The Affiliated Hospital of Xuzhou Medical University; Xuzhou 221004, China.
Background: Polo-like kinase 2 (PLK2) is associated with cardiac fibrosis in patients with atrial fibrillation. However, the role of PLK2 in sepsis-induced cardiac injury has not been fully elucidated. We hypothesize that PLK2 may participate in the progression of sepsis-induced cardiac injury.
View Article and Find Full Text PDFAutophagy
January 2025
Laboratory of Molecular Neuropathology, Department of Pharmacology, Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China.
The aggregation and transmission of SNCA/α-synuclein (synuclein, alpha) is a hallmark pathology of Parkinson disease (PD). PLK2 (polo like kinase 2) is an evolutionarily conserved serine/threonine kinase that is more abundant in the brains of all family members, is highly expressed in PD, and is linked to SNCA deposition. However, in addition to its role in phosphorylating SNCA, the role of PLK2 in PD and the mechanisms involved in triggering neurodegeneration remain unclear.
View Article and Find Full Text PDFBioorg Med Chem
December 2024
Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 1050 Boyles St., Frederick, MD 21702, USA.
Polo-like kinase 1 (Plk1) is an important cell cycle regulator that is a recognized target for development of anti-cancer therapeutics. Plk1 is composed of a catalytic kinase domain (KD), a flexible interdomain linker and a polo-box domain (PBD). Intramolecular protein-protein interactions (PPIs) between the PBD and KD result in "auto-inhibition" that is an essential component of proper Plk1 function.
View Article and Find Full Text PDFFront Cell Dev Biol
December 2024
School of Life Sciences, Zhengzhou University, Zhengzhou, China.
Polo-like kinase 1 (PLK1), a key regulator of the G2/M phase in mitosis, is frequently overexpressed in numerous tumors. Although PLK1 inhibitors have emerged as promising therapeutic agents for cancer, their use has been linked to significant anemia in a subset of patients, yet the underlying mechanisms remain poorly understood. In this study, we utilized an human umbilical cord blood-derived CD34 cell-based erythroid differentiation system, alongside a murine model, to investigate the impact of PLK1 inhibitors on erythropoiesis.
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