SETD7 promotes LC3B methylation and degradation in ovarian cancer

Ziwei Zhang1, Mingyang Li1, Yanan Hou1

  • 1Department of Basic Medicine, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China.

PubMed

Insights

This study reveals SET domain containing lysine methyltransferase 7 (SETD7) methylates Microtubule-associated protein 1 light chain 3 B (LC3B) at K51. This methylation promotes LC3B degradation, reduces autophagosome formation, and drives ovarian cancer progression.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Cancer Research

Background:

  • Microtubule-associated protein 1 light chain 3 (LC3) is crucial for autophagy.
  • Post-translational modifications regulate LC3 function.
  • LC3 methylation and its physiological roles remain largely unknown.

Purpose of the Study:

  • To investigate the role of LC3 protein methylation.
  • To identify the enzyme responsible for LC3 methylation.
  • To elucidate the functional and oncogenic significance of LC3 methylation.

Main Methods:

  • Co-immunoprecipitation to detect protein interactions.
  • In vitro methylation assays.
  • Western blotting to assess protein levels and ubiquitination.
  • Cell culture and functional assays in ovarian cancer cells.

Main Results:

  • SET domain containing lysine methyltransferase 7 (SETD7) directly interacts with and methylates LC3B at lysine 51 (K51).
  • SETD7-mediated LC3B methylation enhances LC3B ubiquitination and degradation.
  • This leads to reduced autophagosome formation.
  • SETD7 promotes ovarian cancer cell proliferation in a K51 methylation-dependent manner.

Conclusions:

  • LC3B K51 methylation is a novel post-translational modification.
  • SETD7-induced LC3B methylation and degradation contribute to ovarian cancer progression.
  • This pathway represents a potential therapeutic target in ovarian cancer.