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In Vitro Polymerization of F-actin on Early Endosomes
Published on: August 28, 2017
Self-assembly and binding of a sorting nexin to sorting endosomes
R C Kurten1, A D Eddington, P Chowdhury
1Department of Physiology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-0750, USA. KurtenRichardC@exchange.uams.edu
Journal of Cell Science
|April 20, 2001
Summary
Sorting nexin 1 (SNX1) self-assembles into complexes and binds to early/sorting endosomes. This protein plays a role in endosomal retention, preventing protein recycling and influencing endosome structure.
Area of Science:
- Cell Biology
- Molecular Biology
- Protein Trafficking
Background:
- Endosomes are key organelles for processing endocytosed materials.
- Endosomal retention prevents the recycling of specific proteins.
- Sorting nexins (SNXs) are implicated in endosomal sorting and trafficking.
Purpose of the Study:
- To investigate the self-assembly and endosomal binding properties of sorting nexin 1 (SNX1).
- To determine the role of SNX1 in endosomal retention and protein sorting.
- To characterize the in vivo oligomeric state and localization of SNX1.
Main Methods:
- In vitro self-assembly assays
- Size-exclusion chromatography
- Green fluorescent protein (GFP) fusions
- Fluorescence recovery after photobleaching (FRAP)
- Fluorescence resonance energy transfer (FRET)
- Video microscopy
Main Results:
- SNX1 self-assembles in vitro and in vivo into tetrameric and larger complexes.
- SNX1 exists in equilibrium between cytoplasmic and endosome-bound pools.
- SNX1-coated endosomes exhibit features of sorting endosomes, including vesicle budding and tubule formation.
- SNX1 is part of larger soluble complexes in the cytosol.
Conclusions:
- SNX1 self-assembly and oligomerization are crucial for its function.
- SNX1's dynamic association with endosomal membranes suggests a role in regulating endosomal trafficking.
- SNX1 contributes to endosomal retention and the sorting of endocytosed cargo.
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