All proposals

Compare actin filament compression between different fiber-scale simulators

2
2

We have previously compared simulations of single actin filament compression at monomer- and fiber-scales using the ReaDDy and Cytosim simulation engines, respectively, under different compression velocities. To better understand how these difference we observed may be specific to the choice of simulators, we proposed running an additional comparison between two simulators at fiber scale.

Interactive visualizations of the previous simulations are available at here.

Proposed by:

Megan Riel-Mehan

Publication

https://www.micropublication.org/journals/biology/micropub-biology-001347

Preliminary Findings

Fiber-scale simulations of single actin filament compression (using Cytosim) were not able to capture filament supertwist behavior observed with monomer-scale simulations (using ReaDDy).

an externally linked image
an externally linked image
An unrelated image from our website showing lots and lots of cells.
An unrelated image from our website showing lots and lots of cells.

Suggested next steps:

  • Build a MEDYAN model for compression of a single actin filament
  • Run simulations at different compression velocities
  • Use the subcell-pipeline to align filaments, perform dimensionality reduction, and calculate metrics

Resources

  • test software tool

    a description for the tool

  • Simularium

    3D Agent based modeling.

  • Actin compression simulation dataset

    ### Overview This dataset contains simulated data of actin filaments using the monomer-scale model [ReaDDy](https://github.com/simularium/readdy-models) and fiber-scale model [Cytosim](https://github.com/simularium/Cytosim). Simulation conditions test compression of a single 500 nm actin filament at different velocities, as well as control simulations with no compression. Compression simulations use the prefix `ACTIN_COMPRESSION_VELOCITY`; control simulations use the prefix `ACTIN_NO_COMPRESSION`. Compression simulation keys include the following: - `0047` = 4.7 μm/s - `0150` = 15 μm/s - `0470` = 47 μm/s - `1500` = 150 μm/s For _ReaDDy_, the actin filament is composed of particles, each representing an actin monomer, initialized based on measurements from an actin crystal structure. Compression was implemented by linearly displacing the three monomers at the pointed end for one time step and then allowing the structure to relax for nine time steps, until the fiber was compressed to 350 nm. Each simulation condition contains 5 replicates. For _Cytosim_, the actin filament is modeled as a 500 nm fiber anchored by two fiber-binding linkers spaced 10 nm apart at each end. The linkers on one of the ends were translated linearly for one time step and allowed to relax for nine time steps, until the fiber was compressed to 350 nm. Each simulation condition contains 5 replicates, with replicates corresponding to random seeds 1, 2, 3, 4, and 5. ### Usage For documentation on how to use and interact with this dataset please refer to [https://docs.quiltdata.com/walkthrough/getting-data-from-a-package](https://docs.quiltdata.com/walkthrough/getting-data-from-a-package). ### License For questions on licensing please refer to [https://www.allencell.org/terms-of-use.html](https://www.allencell.org/terms-of-use.html).

  • Materials and methods available:

    Data and tools made available for use by researchers, that may be of use in pursuing this idea, some available free online, and some available to be purchased or licensed through AICS.
    • actin
    • computational modeling