RASSF1A disrupts the NOTCH signaling axis via SNURF/RNF4-mediated ubiquitination of HES1

EMBO Rep. 2022 Feb 3;23(2):e51287. doi: 10.15252/embr.202051287. Epub 2021 Dec 13.


RASSF1A promoter methylation has been correlated with tumor dedifferentiation and aggressive oncogenic behavior. Nevertheless, the underlying mechanism of RASSF1A-dependent tumor dedifferentiation remains elusive. Here, we show that RASSF1A directly uncouples the NOTCH-HES1 axis, a key suppressor of differentiation. Interestingly, the crosstalk of RASSF1A with HES1 occurs independently from the signaling route connecting RASSF1A with the Hippo pathway. At the molecular level, we demonstrate that RASSF1A acts as a scaffold essential for the SUMO-targeted E3 ligase SNURF/RNF4 to target HES1 for degradation. The reciprocal relationship between RASSF1A and HES1 is evident across a wide range of human tumors, highlighting the clinical significance of the identified pathway. We show that HES1 upregulation in a RASSF1A-depleted environment renders cells non-responsive to the downstream effects of γ-secretase inhibitors (GSIs) which restrict signaling at the level of the NOTCH receptor. Taken together, we report a mechanism through which RASSF1A exerts autonomous regulation of the critical Notch effector HES1, thus classifying RASSF1A expression as an integral determinant of the clinical effectiveness of Notch inhibitors.

Keywords: Hippo-Notch signaling crosstalk; RASSF1A-HES1-SNURF/RNF4 complex; cancer stemness; γ-secretase inhibitors (GSIs).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Humans
  • Nuclear Proteins / metabolism
  • Receptors, Notch* / genetics
  • Receptors, Notch* / metabolism
  • Signal Transduction*
  • Transcription Factor HES-1* / genetics
  • Transcription Factor HES-1* / metabolism
  • Tumor Suppressor Proteins* / genetics
  • Tumor Suppressor Proteins* / metabolism
  • Ubiquitin-Protein Ligases / genetics
  • Ubiquitin-Protein Ligases / metabolism
  • Ubiquitination


  • Nuclear Proteins
  • RASSF1 protein, human
  • RNF4 protein, human
  • Receptors, Notch
  • SNURF protein, human
  • Transcription Factor HES-1
  • Tumor Suppressor Proteins
  • HES1 protein, human
  • Ubiquitin-Protein Ligases