Beating the ER: novel insights into FAM134B function and regulation
Chiara De Leonibus1, Laura Cinque1, Carmine Settembre1,2
1Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.
The EMBO Journal
|February 20, 2020
Summary
Endoplasmic reticulum (ER) degradation, known as ER-phagy, requires receptor FAM134B to fragment ER membranes. This process, driven by CAMK2B phosphorylation, is crucial for cellular homeostasis and is implicated in sensory neuropathy.
Area of Science:
- Cell Biology
- Autophagy Research
- Molecular Neuroscience
Background:
- Cellular homeostasis relies on the endoplasmic reticulum (ER) undergoing selective removal of damaged fragments through ER-phagy.
- ER-phagy is a receptor-mediated form of autophagy essential for maintaining ER integrity.
Purpose of the Study:
- To elucidate the mechanism by which the autophagy receptor FAM134B mediates ER membrane fragmentation during ER-phagy.
- To investigate the role of CAMK2B-mediated phosphorylation in FAM134B function and ER membrane scission.
Main Methods:
- Investigated FAM134B oligomerization and its role in ER membrane fragmentation.
- Utilized biochemical assays to study CAMK2B-mediated phosphorylation of FAM134B.
- Examined alterations in ER-phagy in the context of sensory neuropathy.
Main Results:
- FAM134B mediates ER membrane fragmentation, the initial step in ER-phagy.
- A dynamic model of FAM134B protein oligomerization and ER membrane scission was proposed.
- CAMK2B-mediated phosphorylation drives FAM134B oligomerization and ER scission.
- These mechanisms are altered in sensory neuropathy.
Conclusions:
- FAM134B's dynamic oligomerization, regulated by CAMK2B phosphorylation, is key to ER membrane fragmentation in ER-phagy.
- Dysregulation of this process is linked to sensory neuropathy, highlighting its physiological importance.
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