ERAD Tuning of the HRD1 Complex Component AtOS9 Is Modulated by an ER-Bound E2, UBC32

Dear Editor When membrane proteins and secretory proteins are incom- pletely folded or mis-folded, they are retained in the endo- plasmic reticulum （ER） for further folding or degradation. Two major degradation systems involved in removing the mis-folded or unfolded proteins retained in the ER have been identified： ER-associated degradation （ERAD）, which targets misfolded proteins for ubiquitination and subsequent degradattion through the proteasome pathway （McCracken and Brodsky, 1996）.