Hip2 interacts with cyclin B1 and promotes its degradation through the ubiquitin proteasome pathway.

Hip2, a ubiquitin conjugating enzyme, is involved in the suppression of cell death. The present study revealed that Hip2 regulates the stability of the apoptotic and cell cycle regulator cyclin B1. Hip2 was found to interact with cyclin B1 to promote its degradation through the ubiquitin proteasome pathway. As a result, Hip2 significantly blocked cell death induced by the cyclin B1 protein, suggesting that Hip2 is involved in the regulation of cyclin B1-mediated cell death.