Letter abstract
Nature Chemical Biology 2, 83 - 86 (2006)
Published online: 15 January 2006 | doi:10.1038/nchembio763
Dynamic polymorphism of single actin molecules in the actin filament
Jun Kozuka1,2,5, Hiroaki Yokota3,5, Yoshiyuki Arai1,2, Yoshiharu Ishii1 & Toshio Yanagida1,2,4
Actin filament dynamics are critical in cell motility1, 2. The structure of actin filament changes spontaneously and can also be regulated by actin-binding proteins, allowing actin to readily function in response to external stimuli1. The interaction with the motor protein myosin changes the dynamic nature of actin filaments3, 4. However, the molecular bases for the dynamic processes of actin filaments are not well understood. Here, we observed the dynamics of rabbit skeletal-muscle actin conformation by monitoring individual molecules in the actin filaments using single-molecule fluorescence resonance energy transfer (FRET)5, 6, 7 imaging with total internal reflection fluorescence microscopy (TIRFM)8. The time trajectories of FRET show that actin switches between low- and high-FRET efficiency states on a timescale of seconds. If actin filaments are chemically cross-linked, a state that inhibits myosin motility9, the equilibrium shifts to the low-FRET conformation, whereas when the actin filament is interacting with myosin, the high-FRET conformation is favored. This dynamic equilibrium suggests that actin can switch between active and inactive conformations in response to external signals.
- Formation of Soft Nanomachines, Core Research for Evolution Science and Technology, Japan Science and Technology Agency, Suita, Osaka, 563-0871, Japan.
- Department of Biophysical Engineering, Osaka University, 1-3, Machikaneyama, Toyonaka, Osaka 560-8531, Japan.
- Department of Molecular Physiology, The Tokyo Metropolitan Institute of Medical Science, 3-18-22, Honkomagome, Bunkyo-ku, Tokyo 113-8613, Japan.
- Soft Biosystem Group, Laboratories for Nanobiology, Graduate School of Frontier Biosciences, University of Osaka, 1-3, Yamadaoka, Suita, Osaka, 565-0871, Japan.
- These authors contributed equally to this work.
Correspondence to: Toshio Yanagida1,2,4 e-mail: yanagida@phys1.med.osaka-u.ac.jp
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated.
NEWS AND VIEWS
Muscle Support for the lever armNature News and Views (26 Nov 1998)
Happy motoring with ATP synthaseNature Structural & Molecular Biology News and Views (01 Feb 2004)
RESEARCH
Proton-powered subunit rotation in single membrane-bound F 0 F 1 -ATP synthaseNature Structural & Molecular Biology Article (01 Feb 2004)
Movements of the ϵ-subunit during catalysis and activation in single membrane-bound H + -ATP synthaseThe EMBO Journal Article (15 Jun 2005)
See all 47 matches for Research
