FBXO32 links ubiquitination to epigenetic reprograming of melanoma cells

Cell Death Differ. 2021 Jun;28(6):1837-1848. doi: 10.1038/s41418-020-00710-x. Epub 2021 Jan 18.

Abstract

Ubiquitination by serving as a major degradation signal of proteins, but also by controlling protein functioning and localization, plays critical roles in most key cellular processes. Here, we show that MITF, the master transcription factor in melanocytes, controls ubiquitination in melanoma cells. We identified FBXO32, a component of the SCF E3 ligase complex as a new MITF target gene. FBXO32 favors melanoma cell migration, proliferation, and tumor development in vivo. Transcriptomic analysis shows that FBXO32 knockdown induces a global change in melanoma gene expression profile. These include the inhibition of CDK6 in agreement with an inhibition of cell proliferation and invasion upon FBXO32 silencing. Furthermore, proteomic analysis identifies SMARC4, a component of the chromatin remodeling complexes BAF/PBAF, as a FBXO32 partner. FBXO32 and SMARCA4 co-localize at loci regulated by FBXO32, such as CDK6 suggesting that FBXO32 controls transcription through the regulation of chromatin remodeling complex activity. FBXO32 and SMARCA4 are the components of a molecular cascade, linking MITF to epigenetics, in melanoma cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cell Proliferation
  • Cellular Reprogramming / genetics*
  • Epigenesis, Genetic / genetics*
  • Humans
  • Melanoma / genetics*
  • Melanoma / pathology
  • Mice
  • Mice, Nude
  • Muscle Proteins / metabolism*
  • Proteomics / methods*
  • SKP Cullin F-Box Protein Ligases / metabolism*
  • Transfection
  • Ubiquitination
  • Xenograft Model Antitumor Assays

Substances

  • Muscle Proteins
  • Fbxo32 protein, mouse
  • SKP Cullin F-Box Protein Ligases