The tomato DWD motif-containing protein DDI1 interacts with the CUL4-DDB1-based ubiquitin ligase and plays a pivotal role in abiotic stress responses

Biochem Biophys Res Commun. 2014 Aug 8;450(4):1439-45. doi: 10.1016/j.bbrc.2014.07.011. Epub 2014 Jul 10.


CULLIN4(CUL4)-DAMAGED DNA BINDING PROTEIN1 (DDB1)-based ubiquitin ligase plays significant roles in multiple physiological processes via ubiquitination-mediated degradation of relevant target proteins. The DDB1-CUL4-associated factor (DCAF) acts as substrate receptor in the CUL4-DDB1 ubiquitin ligase complex and determines substrate specificity. In this study, we identified a tomato (Solanum lycopersicum) DDB1-interacting (DDI1) protein as a DCAF protein involved in response to abiotic stresses, including UV radiation, high salinity and osmotic stress. Co-immunoprecipitation and bimolecular fluorescence complementation assay indicated that DDI1 associates with CUL4-DDB1 in the nucleus. Quantitative RT-PCR analysis indicated the DDI1 gene is induced by salt, mannitol and UV-C treatment. Moreover, transgenic tomato plants with overexpression or knockdown of the DDI1 gene exhibited enhanced or attenuated tolerance to salt/mannitol/UV-C, respectively. Thus, our data suggest that DDI1 functions as a substrate receptor of the CUL4-DDB1 ubiquitin ligase, positively regulating abiotic stress response in tomato.

Keywords: Abiotic stress; CUL4–DDB1; DCAF protein; DDI1; Tomato.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Nucleus / metabolism
  • Osmotic Pressure
  • Plant Proteins / chemistry
  • Plant Proteins / metabolism*
  • Solanum lycopersicum / chemistry*
  • Stress, Physiological*
  • Two-Hybrid System Techniques
  • Ubiquitin-Protein Ligases / metabolism*
  • Ultraviolet Rays


  • Plant Proteins
  • Ubiquitin-Protein Ligases