Year: 2024
Type: article
Abstract: Endoplasmic reticulum quality control is crucial for maintaining cellular homeostasis and adapting to stress conditions. Although several ER-phagy receptors have been identified, the collaboration between cytosolic and ER-resident factors in ER fragmentation and ER-phagy regulation remains unclear. Here, we perform a phenotype-based gain-of-function screen and identify a cytosolic protein, FKBPL, functioning as an ER-phagy regulator. Overexpression of FKBPL triggers ER fragmentation and ER-phagy. FKBPL has multiple protein binding domains, can self-associate and might act as a scaffold connecting CKAP4 and LC3/GABARAPs. CKAP4 serves as a bridge between FKBPL and ER-phagy cargo. ER-phagy-inducing conditions increase FKBPL-CKAP4 interaction followed by FKBPL oligomerization at the ER, leading to ER-phagy. In addition, FKBPL-CKAP4 deficiency leads to Golgi disassembly and lysosome impairment, and an increase in ER-derived secretory vesicles and enhances cytosolic protein secretion via microvesicle shedding. Taken together, FKBPL with the aid of CKAP4 induces ER fragmentation and ER-phagy, and FKBPL-CKAP4 deficiency facilitates protein secretion. ER quality control is crucial to maintain cellular homeostasis. Here, the authors identify a cytosolic ER-phagy regulator inducing ER fragmentation and ER-phagy that functions with an ER-resident receptor, finding a collaboration between cytosolic and ER-resident proteins in quality control.
Source: Nature Communications
Institution: Seoul National University
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $6,790
Awards: G2034272852, G5956414574, G8046495442
OpenAlex ID: W4402346608