Protective role of the endoplasmic reticulum protein mitsugumin23 against ultraviolet C-induced cell death

• Knockdown of the ER protein mitsugumin23 (MG23) enhances UVC-induced cell death.
• The small heat shock protein αB-crystallin was identified as a MG23 binder.
• Knockdown of αB-crystallin enhances UVC-induced cell death.
• The ER-anchored mutant of αB-crystallin is protective against UVC.
• MG23 protects cells against UVC partly by recruiting αB-crystallin to the ER.

The endoplasmic reticulum (ER) operates in adaptive responses to various stresses, dictating cell fate. Here we show that knockdown of the ER protein mitsugumin23 (MG23) enhances cell death induced by ultraviolet C (UVC), which causes DNA damage. The small heat shock protein αB-crystallin (αBC) is identified as a MG23 binding molecule and its knockdown facilitates death of UVC-exposed cells. Conversely, αBC lowered UVC sensitivity when expressed as an ER-anchored form. Taken together, the results suggest that MG23 plays a protective role against UVC by accumulating αBC in the close vicinity of the ER.

Structured summary of protein interactionMG23 physically interacts with αBC by anti tag coimmunoprecipitation (View interaction)MG23 physically interacts with αBC by two hybrid (View interaction)