UBC13 is an RNF213‐associated E2 ubiquitin‐conjugating enzyme, and Lysine 63‐linked ubiquitination by the RNF213‐UBC13 axis is responsible for angiogenic activity

Moyamoya disease (MMD) is a cryptogenic vascular disorder in the intracranial arteries. RING protein 213 (RNF213) is the susceptibility gene for MMD, and encodes a RING domain and a Walker motif. Herein, we identified UBC13 (UBE2N) as an E2 ubiquitin‐conjugating enzyme for RNF213 E3 ubiquitin ligase by yeast two‐hybrid screening with a fragment containing RNF213 RING domain as bait, and the immunocomplex of RNF213‐UBC13 was detected in vivo. Analysis of the ubiquitin chain on RNF213 by monitoring autoubiquitination showed that RNF213 was autoubiquitinated in a K63 chain fashion, but not in a K48 chain fashion. Finally, this RNF213 ubiquitination in a UBC13‐dependent manner was required for cell mobility and invasion activity for HUVEC cells in UBC13 knock‐down and ubiquitination‐dead RNF213 mutant expressing experiments. These findings demonstrated that RNF213 is a K63‐linked E3 ubiquitin ligase, and UBC13 is responsible for RNF213 dependent ubiquitination. The RNF213‐UBC13 axis may be associated with angiogenic activity and MMD.