Related Experiment Video

Updated: May 30, 2025

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay
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Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay

Published on: May 3, 2018

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Structural mechanism for recognition of E2F1 by the ubiquitin ligase adaptor Cyclin F

Peter Ngoi1, Xianxi Wang2, Sivasankar Putta1

  • 1Department of Chemistry and Biochemistry, University of California, Santa Cruz, CA.

Biorxiv : the Preprint Server for Biology
|January 27, 2025
PubMed

Insights

Cyclin F, a unique cell-cycle regulator, acts as a substrate receptor in E3 ubiquitin ligase complexes. Structural analysis reveals distinct E2F1 binding mechanisms compared to Cyclin A, advancing understanding of cell cycle control.

Area of Science:

  • Molecular Biology
  • Structural Biology
  • Biochemistry

Background:

  • Cyclin F is a non-canonical cyclin regulating cell-cycle transitions.
  • Unlike canonical cyclins, Cyclin F functions as a substrate receptor in SCF E3 ubiquitin ligase complexes.
  • Mechanisms of Cyclin F's selective substrate recruitment, especially compared to Cyclin A, are poorly understood.

Purpose of the Study:

  • To elucidate the structural features of Cyclin F responsible for substrate recognition.
  • To investigate the molecular basis for Cyclin F's substrate selectivity over Cyclin A.
  • To understand the regulation of E2F1 by Cyclin F.

Main Methods:

  • Single-particle cryo-electron microscopy (cryo-EM) was used to determine the structure of a Cyclin F-Skp1 complex bound to an E2F1 peptide.
  • Biochemical analyses were performed to compare substrate-binding properties.

Main Results:

  • The study revealed distinct structural differences in the substrate-binding site of Cyclin F compared to Cyclin A.
  • Electrostatic interactions at the E2F1 binding interface were identified as crucial and differ between Cyclin F and Cyclin A.
  • Findings expand upon the known cyclin-binding motifs (Cy or RxL).

Conclusions:

  • Cyclin F possesses unique structural and electrostatic features for E2F1 binding, differentiating it from Cyclin A.
  • This research advances the understanding of E2F1 regulation by Cyclin F.
  • The findings may guide the development of targeted Cyclin F inhibitors.

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