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The Antiparallel Dimerization of Myosin X Imparts Bundle Selectivity for Processive Motility
Matthew A Caporizzo1, Claire E Fishman1, Osamu Sato2
1Department of Physiology, Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
Biophysical Journal
|March 29, 2018
Summary
Antiparallel myosin X dimers show selective movement on bundled actin filaments, unlike parallel dimers. This selectivity is crucial for understanding myosin X
Area of Science:
- Cell biology
- Molecular motors
- Biophysics
Background:
- Myosin X is a molecular motor essential for cell migration and filopodia formation.
- Its unique antiparallel dimerization is key to its function, but the targeting mechanism remains unclear.
Purpose of the Study:
- To investigate if antiparallel dimerization of myosin X leads to selective binding on actin bundles.
- To compare the motility of parallel and antiparallel myosin X dimers on single and bundled actin filaments.
Main Methods:
- Comparing motility of antiparallel and parallel myosin X dimers on single and fascin-bundled actin filaments.
- Utilizing a mathematical model to correlate motility parameters with biochemical and mechanical kinetics.
Main Results:
- Antiparallel myosin X dimers selectively move on fascin-bundled actin filaments.
- These dimers show weak processivity on single actin filaments, unlike robustly processive parallel dimers.
- Mathematical modeling suggests lower forward binding probability for antiparallel myosin X on single actin filaments.
Conclusions:
- Antiparallel dimerization confers selectivity for actin bundles in myosin X.
- This selectivity is linked to differences in binding kinetics and processivity compared to parallel dimers.
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