Ubiquitin-proteasome pathway is a major pathway to regulate cell protein stability in eukaryotes including plants. E3 ubiquitin ligase in the ubiquitin- proteasome pathway is responsible for recruiting specific target proteins for ubiquitination. DDB1 acts together with a second protein, the substrate receptor, totarget substrates for CUL4-based E3 ligase. The yeast two-hybrid assay and BIFC have been applied to check the interaction between AtDWD and DDB1a/DDB1b in vitro and in vivo. Experimental results have shown that interaction between AtDWD and DDB1b is strong in vitro and in vivo，and the C-terminal of AtDWD is where the interaction happens. Support that AtDWD has the potential to be a substrate receptor protein of CUL4-based E3 ligase.
