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Published on: August 10, 2021
Structural basis for membrane remodeling by the AP5-SPG11-SPG15 complex.
Xinyi Mai1, Yang Wang1, Xi Wang1
1Kobilka Institute of Innovative Drug Discovery, School of Medicine, The Chinese University of Hong Kong, Shenzhen, Guangdong, China.
The spastizin (SPG15) and spatacsin (SPG11) complex, crucial for lysosome formation and linked to spastic paraplegia, interacts with the AP5 complex. This AP5-SPG11-SPG15 complex remodels membranes, essential for autolysosome tubulation.
Area of Science:
- Cell Biology
- Structural Biology
- Neurogenetics
Background:
- Mutations in spastizin (SPG15) and spatacsin (SPG11) cause hereditary spastic paraplegia.
- The SPG11-SPG15 complex collaborates with the adaptor protein complex AP5 in membrane trafficking.
Purpose of the Study:
- To elucidate the structural assembly of the AP5-SPG11-SPG15 complex.
- To understand the functional role of this complex in membrane remodeling and lysosome formation.
Main Methods:
- Cryogenic-electron microscopy (cryo-EM) for structural determination.
- In silico predictions for computational analysis.
- In vitro assays to assess membrane remodeling capabilities.
Main Results:
- The SPG11-SPG15 complex forms a W-shaped structure.
- The N-terminal region of SPG11 mediates AP5 complex binding and assembly.
- The AP5-SPG11-SPG15 complex binds PI3P, senses membrane curvature, and drives membrane remodeling.
Conclusions:
- The AP5-SPG11-SPG15 complex plays a key role in membrane dynamics.
- This complex is essential for initiating autolysosome tubulation, providing insights into spastic paraplegia pathogenesis.
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