Discriminative SKP2 Interactions with CDK-Cyclin Complexes Support a Cyclin A-Specific Role in p27KIP1 Degradation

J Mol Biol. 2021 Mar 5;433(5):166795. doi: 10.1016/j.jmb.2020.166795. Epub 2021 Jan 7.

Abstract

The SCFSKP2 ubiquitin ligase relieves G1 checkpoint control of CDK-cyclin complexes by promoting p27KIP1 degradation. We describe reconstitution of stable complexes containing SKP1-SKP2 and CDK1-cyclin B or CDK2-cyclin A/E, mediated by the CDK regulatory subunit CKS1. We further show that a direct interaction between a SKP2 N-terminal motif and cyclin A can stabilize SKP1-SKP2-CDK2-cyclin A complexes in the absence of CKS1. We identify the SKP2 binding site on cyclin A and demonstrate the site is not present in cyclin B or cyclin E. This site is distinct from but overlapping with features that mediate binding of p27KIP1 and other G1 cyclin regulators to cyclin A. We propose that the capacity of SKP2 to engage with CDK2-cyclin A by more than one structural mechanism provides a way to fine tune the degradation of p27KIP1 and distinguishes cyclin A from other G1 cyclins to ensure orderly cell cycle progression.

Keywords: cell cycle; checkpoint; protein kinase; signaling; ubiquitination.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • CDC2-CDC28 Kinases / chemistry
  • CDC2-CDC28 Kinases / genetics
  • CDC2-CDC28 Kinases / metabolism
  • Cyclin A / chemistry*
  • Cyclin A / genetics
  • Cyclin A / metabolism
  • Cyclin E / chemistry
  • Cyclin E / genetics
  • Cyclin E / metabolism
  • Cyclin-Dependent Kinase 2 / chemistry*
  • Cyclin-Dependent Kinase 2 / genetics
  • Cyclin-Dependent Kinase 2 / metabolism
  • Cyclin-Dependent Kinase Inhibitor p27 / chemistry*
  • Cyclin-Dependent Kinase Inhibitor p27 / genetics
  • Cyclin-Dependent Kinase Inhibitor p27 / metabolism
  • G1 Phase Cell Cycle Checkpoints*
  • Gene Expression Regulation
  • HEK293 Cells
  • Humans
  • Protein Binding
  • Protein Conformation, alpha-Helical
  • Protein Conformation, beta-Strand
  • Protein Interaction Domains and Motifs
  • Proteolysis
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • S-Phase Kinase-Associated Proteins / chemistry*
  • S-Phase Kinase-Associated Proteins / genetics
  • S-Phase Kinase-Associated Proteins / metabolism
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Signal Transduction

Substances

  • CDKN1B protein, human
  • CKS1B protein, human
  • Cyclin A
  • Cyclin E
  • Recombinant Proteins
  • S-Phase Kinase-Associated Proteins
  • SKP1 protein, human
  • SKP2 protein, human
  • Cyclin-Dependent Kinase Inhibitor p27
  • CDC2-CDC28 Kinases
  • CDK2 protein, human
  • Cyclin-Dependent Kinase 2