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Updated: Jun 6, 2025

Using Caenorhabditis elegans as a Model System to Study Protein Homeostasis in a Multicellular Organism
Published on: December 18, 2013
ER quality control through reticulophagy and protein secretion
Cathena Meiling Li1, Yong-Keun Jung1
1School of Biological Sciences, Seoul National University, Seoul, Korea.
Abstract:
The endoplasmic reticulum (ER) is the site of multiple cellular events and maintaining its quality control is thus crucial for cell homeostasis. Through a morphology-based gain-of-function screen, we identified the cytosolic protein FKBPL as a regulator of reticulophagy. With multiple protein-binding domains, FKBPL binds to the ER-resident CKAP4, acting as a bridge that connects the ER to the phagophore and facilitating the delivery of ER contents for lysosomal degradation. The FKBPL-CKAP4 axis is essential for both basal and stress-induced reticulophagy. Loss of the FKBPL-CKAP4 interaction attenuates reticulophagy and enhances protein secretion via microvesicle shedding. Here, we propose a dual role for the FKBPL-CKAP4 axis in regulating reticulophagy and protein secretion.
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