The Cullin 3 substrate adaptor KLHL20 mediates DAPK ubiquitination to control interferon responses

EMBO J. 2010 May 19;29(10):1748-61. doi: 10.1038/emboj.2010.62. Epub 2010 Apr 13.

Abstract

Death-associated protein kinase (DAPK) was identified as a mediator of interferon (IFN)-induced cell death. How IFN controls DAPK activation remains largely unknown. Here, we identify the BTB-Kelch protein KLHL20 as a negative regulator of DAPK. KLHL20 binds DAPK and Cullin 3 (Cul3) via its Kelch-repeat domain and BTB domain, respectively. The KLHL20-Cul3-ROC1 E3 ligase complex promotes DAPK polyubiquitination, thereby inducing the proteasomal degradation of DAPK. Accordingly, depletion of KLHL20 diminishes DAPK ubiquitination and degradation. The KLHL20-mediated DAPK ubiquitination is suppressed in cells receiving IFN-alpha or IFN-gamma, which induces an enrichment/sequestration of KLHL20 in the PML nuclear bodies, thereby separating KLHL20 from DAPK. Consequently, IFN triggers the stabilization of DAPK. This mechanism of DAPK stabilization is crucial for determining IFN responsiveness of tumor cells and contributes to IFN-induced autophagy. This study identifies KLHL20-Cul3-ROC1 as an E3 ligase for DAPK ubiquitination and reveals a regulatory mechanism of DAPK, through blocking its accessibility to this E3 ligase, in IFN-induced apoptotic and autophagic death. Our findings may be relevant to the problem of IFN resistance in cancer therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Animals
  • Apoptosis Regulatory Proteins / metabolism
  • Autophagy
  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism
  • Carrier Proteins / chemistry*
  • Cullin Proteins / chemistry*
  • Death-Associated Protein Kinases
  • Gene Expression Regulation*
  • HeLa Cells
  • Humans
  • Interferons / chemistry*
  • Interferons / metabolism
  • Mice
  • Models, Biological
  • NIH 3T3 Cells
  • Neoplasms / therapy
  • Phenotype
  • Ubiquitin / chemistry*
  • Ubiquitin-Protein Ligases / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Apoptosis Regulatory Proteins
  • CUL3 protein, human
  • Carrier Proteins
  • Cullin Proteins
  • KLHL20 protein, human
  • Ubiquitin
  • Interferons
  • Ubiquitin-Protein Ligases
  • Death-Associated Protein Kinases
  • Calcium-Calmodulin-Dependent Protein Kinases