Membrane composition and curvature in SNX9-mediated actin polymerization
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View abstract on PubMed
Summary
This summary is machine-generated.Sorting nexin 9 (SNX9) is a scaffold protein involved in viral uptake and cancer. This study reveals SNX9
Area Of Science
- Biochemistry
- Cell Biology
- Molecular Medicine
Background
- Sorting nexin 9 (SNX9) is a scaffold protein implicated in viral uptake, inflammation, and cancer progression.
- SNX9 participates in endocytosis and the formation of mitochondrial-derived vesicles.
- Its Bin-Amphiphysin-Rvs (BAR)-Phox homology (PX) domains bind phosphoinositides, and its Src homology 3 (SH3) domain interacts with proteins regulating actin polymerization.
Purpose Of The Study
- To investigate the membrane-binding specificity and actin-remodeling activities of SNX9.
- To elucidate the structural mechanisms underlying SNX9's functions at the membrane.
Main Methods
- Biolayer interferometry to assess binding affinities.
- Cell-free reconstitution assays to study protein interactions.
- Superresolution microscopy (3D-STORM) and cryo-electron tomography to visualize SNX9 structures and actin networks.
Main Results
- SNX9 exhibits preferential binding to liposomes containing PI(4,5)P2 and PI(3)P over PI(3,4)P2.
- Actin assembly is dependent on the combined interactions of SNX9's PX-BAR and SH3 domains.
- SNX9 forms both flat and curved assemblies at actin incorporation sites and builds branched and bundled actin networks.
Conclusions
- SNX9 possesses multifunctional capabilities in actin remodeling.
- Its specific membrane interactions and ability to organize actin networks highlight its critical roles in cellular processes.
- Understanding SNX9's mechanisms may offer insights into cancer and viral pathogenesis.
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