Cryo-electron tomography structure of Arp2/3 complex in cells reveals new insights into the branch junction.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33353942.
- Also identified by DOI 10.1038/s41467-020-20286-x and PMC identifier 7755917.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The actin-related protein (Arp)2/3 complex nucleates branched actin filament networks pivotal for cell migration, endocytosis and pathogen infection. Its activation is tightly regulated and involves complex structural rearrangements and actin filament binding, which are yet to be understood. Here, we report a 9.0 Å resolution structure of the actin filament Arp2/3 complex branch junction in cells using cryo-electron tomography and subtomogram averaging. This allows us to generate an accurate model of the active Arp2/3 complex in the branch junction and its interaction with actin filaments. Notably, our model reveals a previously undescribed set of interactions of the Arp2/3 complex with the mother filament, significantly different to the previous branch junction model. Our structure also indicates a central role for the ArpC3 subunit in stabilizing the active conformation.
Medical subject headings
- Actin-Related Protein 2-3 Complex
- Electron Microscope Tomography
- Fibroblasts