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

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.