The nature of the globular- to fibrous-actin transition

  title={The nature of the globular- to fibrous-actin transition},
  author={Toshiro Oda and Mitsusada Iwasa and Tomoki Aihara and Yuichiro Ma{\'e}da and Akihiro Narita},
Actin plays crucial parts in cell motility through a dynamic process driven by polymerization and depolymerization, that is, the globular (G) to fibrous (F) actin transition. Although our knowledge about the actin-based cellular functions and the molecules that regulate the G- to F-actin transition is growing, the structural aspects of the transition remain enigmatic. We created a model of F-actin using X-ray fibre diffraction intensities obtained from well oriented sols of rabbit skeletal… 

Structural biology: Actin in a twist

The structure of F-actin has been determined at high resolution and it is revealed that the two major domains, which form a propeller-like twist in G-Actin, are untwisted and the molecule is flat in F-actsin.

Cytoskeleton: The making of a filament

  • A. Heinrichs
  • Chemistry, Biology
    Nature Reviews Molecular Cell Biology
  • 2009
The domain rotation that is associated with the Gto F-actin transition moves the crucial Gln137 residue in the ATPase region and the γ-phosphate together, which might allow the bound ATP to be hydrolysed.

Role of the Actin Ala-108–Pro-112 Loop in Actin Polymerization and ATPase Activities*

The attention was focused on the Ala-108–Pro-112 loop, which must play crucial roles in the transition, and the consequences of the amino acid replacements on the polymerization process.

Exploring the stability limits of actin and its suprastructures.

The Central Role of the F-Actin Surface in Myosin Force Generation

Myosin-binding to actin as viewed from the actin surface is discussed, describing conserved structural features of actin required for the binding of all or most myosin isoforms while also noting specific interactions unique to myosIn isoforms.

Structural basis of actin filament assembly and aging

Cryo-EM structures of F-actin in all nucleotide states, polymerized in the presence of Mg2+ or Ca2+, reveal that the G- to F-actsin transition induces the relocation of water molecules in the nucleotide binding pocket, activating one of them for the nucleophilic attack of ATP.

Nucleotide-dependent conformational changes in the actin filament: Subtler than expected

  • R. Dominguez
  • Chemistry
    Proceedings of the National Academy of Sciences
  • 2019
Crystallization has been made possible using one of several strategies that prevent polymerization, including mutagenesis, covalent modification of actin, and the formation of soluble complexes with actin-binding protein (ABPs) or marine toxins.

Computational prediction of actin-actin interaction.

The computational prediction model of actin and actin complex has been constructed base on the atomic model structure of G-actin, and hot spots interactions at the protein interface were identified, that were predicted to contribute substantially to the free energy of binding.

Computational prediction of actin–actin interaction

  • A. Ünlü
  • Biology, Chemistry
    Molecular Biology Reports
  • 2013
The computational prediction model of actin and actin complex has been constructed base on the atomic model structure of G-actin, which provided a detailed prediction of key amino acid interactions at the protein–protein interface.



Structural basis of actin filament capping at the barbed‐end: a cryo‐electron microscopy study

This work presents an EM structure of the complex of the actin filament and hetero‐dimeric capping protein (CP) bound to the barbed‐end at 23 Å resolution, by applying a newly developed methods of image analysis to cryo‐electron micrographs.

The crystal structure of a cross-linked actin dimer suggests a detailed molecular interface in F-actin.

A plausible model of F-actin can be constructed by reintroducing the known filament twist, without disturbing significantly the interface observed in the actin dimer crystal.

Regulation of actin filament assembly by Arp2/3 complex and formins.

  • T. Pollard
  • Biology
    Annual review of biophysics and biomolecular structure
  • 2007
This review summarizes what is known about the biochemical and biophysical mechanisms that initiate the assembly of actin filaments in cells and focuses on Arp2/3 complex and formins.

Atomic model of the actin filament

A unique orientation of the monomer with respect to the actin helix has been found and the main interactions are along the two-start helix with a contribution from a loop extending across the filament axis provided by the molecule in the adjacent strand.

Prokaryotic origin of the actin cytoskeleton

It is demonstrated that the bacterial MreB protein assembles into filaments with a subunit repeat similar to that of F-actin—the physiological polymer of eukaryotic actin, demonstrating that M reB and actin are very similar in three dimensions.

Structural basis of actin filament nucleation and processive capping by a formin homology 2 domain

The crystal structure of the yeast Bni1p FH2 domain in complex with tetramethylrhodamine–actin is reported, showing each of the two structural units in the FH1 dimer binds two actins in an orientation similar to that in an actin filament, suggesting this structure could function as a filament nucleus.

The Crystal Structure of Uncomplexed Actin in the ADP State

The successful crystallization of monomeric actin opens the way to future structure determinations of actin complexes with actin-binding proteins such as myosin.

Crystal Structures of Expressed Non-polymerizable Monomeric Actin in the ADP and ATP States*

This work expressed a cytoplasmic actin in Sf9 cells, which was rendered non-polymerizable by virtue of two point mutations in subdomain 4 (A204E/P243K), and suggests that the nucleotide-dependent formation of the D-loop helix may result from signal propagation through crystal packing interactions.