High-speed superresolution imaging of the proteins in fission yeast clathrin-mediated endocytic actin patches
| Autor: | Julien Berro, Wasim A. Sayyad, Rajesh Arasada, Thomas D. Pollard |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Cytoplasm Endocytic cycle macromolecular substances Endocytosis Clathrin Actin-Related Protein 2-3 Complex Cell membrane Myosin Type I 03 medical and health sciences Schizosaccharomyces medicine Actin filament polymerization Actin-binding protein Molecular Biology Cytoskeleton Actin Cytokinesis biology Cell Membrane Microfilament Proteins Clathrin-Coated Vesicles Articles Cell Biology Actins Actin Cytoskeleton Adaptor Proteins Vesicular Transport 030104 developmental biology medicine.anatomical_structure Microscopy Fluorescence Biophysics biology.protein Schizosaccharomyces pombe Proteins Protein Binding Vesicle scission |
| Zdroj: | Molecular Biology of the Cell |
| ISSN: | 1939-4586 1059-1524 |
| DOI: | 10.1091/mbc.e17-06-0415 |
| Popis: | High-speed superresolution localization microscopy shows that actin filaments assemble in two zones in Schizosaccharomyces pombe actin patches, one around the base of the membrane invagination and another ~200 nm deeper into the cytoplasm. Both zones of actin filaments are important for elongation of the endocytic tubule and membrane scission To internalize nutrients and cell surface receptors via clathrin-mediated endocytosis, cells assemble at least 50 proteins, including clathrin, clathrin-interacting proteins, actin filaments, and actin binding proteins, in a highly ordered and regulated manner. The molecular mechanism by which actin filament polymerization deforms the cell membrane is unknown, largely due to lack of knowledge about the organization of the regulatory proteins and actin filaments. We used high-speed superresolution localization microscopy of live fission yeast cells to improve the spatial resolution to ∼35 nm with 1-s temporal resolution. The nucleation promoting factors Wsp1p (WASp) and Myo1p (myosin-I) define two independent pathways that recruit Arp2/3 complex, which assembles two zones of actin filaments. Myo1p concentrates at the site of endocytosis and initiates a zone of actin filaments assembled by Arp2/3 complex. Wsp1p appears simultaneously at this site but subsequently moves away from the cell surface as it stimulates Arp2/3 complex to assemble a second zone of actin filaments. Cells lacking either nucleation-promoting factor assemble only one, stationary, zone of actin filaments. These observations support our two-zone hypothesis to explain endocytic tubule elongation and vesicle scission in fission yeast. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|