제목 | [논문] 최철용 교수님_The N-Degron pathway mediates ER-phagy | ||||
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작성자 | 비임파성 장기 면역 연구센터 | 등록일 | 2021-01-26 | 조회수 | 823 |
The N-Degron pathway mediates ER-phagy
The endoplasmic reticulum (ER) is susceptible to wear-and-tear and proteotoxic stress, necessitating its turnover.Here,weshowthat theN-degronpathway mediates ER-phagy. This autophagic degradation initiates when the transmembrane E3 ligase TRIM13 (also known as RFP2) is ubiquitinated via the lysine 63 (K63) linkage. K63-ubiquitinated TRIM13 recruits p62 (alsoknownassequestosome-1),whose complex undergoes oligomerization. The oligomerization is induced when the ZZ domain of p62 is bound by the N-terminal arginine (Nt-Arg) of arginylated substrates. Upon activation by the Nt-Arg, oligomerized TRIM13- p62 complexes are separated along with the ER compartments and targeted to autophagosomes, leading to lysosomal degradation. When protein aggregates accumulate within the ER lumen, degradation- resistant autophagic cargoes are co-segregated by ER membranes for lysosomal degradation. We developed synthetic ligands to the p62 ZZ domain that enhance ER-phagy for ER protein quality control and alleviate ER stresses. Our results elucidate the biochemical mechanisms and pharmaceutical means that regulate ER homeostasis. |