Proteomic analysis reveals a PLK1-dependent G2/M degradation program and a role for AKAP2 in coordinating the mitotic cytoskeleton

  • Cell Rep. 2024 Jul 16;43(8):114510. doi: 10.1016/j.celrep.2024.114510.
Ryan D Mouery  1 ,  Kimberly Lukasik  2 ,  Carolyn Hsu  3 ,  Thomas Bonacci  4 ,  Derek L Bolhuis  5 ,  Xianxi Wang  4 ,  C Allie Mills  6 ,  E Drew Toomer  4 ,  Owen G Canterbury  7 ,  Kevin C Robertson  4 ,  Timothy B Branigan  8 ,  Nicholas G Brown  4 ,  Laura E Herring  9 ,  Stephanie L Gupton  10 ,  Michael J Emanuele  11
Affiliations
  • 1. Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
  • 2. Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
  • 3. Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
  • 4. Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
  • 5. Department of Biochemistry and Biophysics, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
  • 6. UNC Proteomics Core Facility, Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
  • 7. Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
  • 8. Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.
  • 9. Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; UNC Proteomics Core Facility, Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
  • 10. Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
  • 11. Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Electronic address: [email protected].
PMID: 39018246 DOI: 10.1016/j.celrep.2024.114510
Abstract

Ubiquitination is an essential regulator of cell division. The kinase Polo-like kinase 1 (PLK1) promotes protein degradation at G2/M phase through the E3 ubiquitin Ligase Skp1-Cul1-F box (SCF)βTrCP. However, the magnitude to which PLK1 shapes the mitotic proteome is uncharacterized. Combining quantitative proteomics with pharmacologic PLK1 inhibition revealed a widespread, PLK1-dependent program of protein breakdown at G2/M. We validated many PLK1-regulated proteins, including substrates of the cell-cycle E3 SCFCyclin F, demonstrating that PLK1 promotes proteolysis through at least two distinct E3 Ligases. We show that the protein-kinase-A-anchoring protein A-kinase anchor protein 2 (AKAP2) is cell-cycle regulated and that its mitotic degradation is dependent on the PLK1/βTrCP signaling axis. Expression of a non-degradable AKAP2 mutant resulted in actin defects and aberrant mitotic spindles, suggesting that AKAP2 degradation coordinates cytoskeletal organization during Mitosis. These findings uncover PLK1's far-reaching role in shaping the mitotic proteome post-translationally and have potential implications in malignancies where PLK1 is upregulated.

Keywords
AKAP2; CP: Cell biology; CP: Molecular biology; Cullin RING Ligase; Cyclin F; G2/M; Plk1; cell cycle; mitosis; protein degradation; ubiquitin; βTRCP.
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