We are examining the force-sensitivity of Acanthamoeba myosin 1c (AM1C) activity. Class 1 myosins have been split into two subclasses. While subclass 2 myosins are hypothesized to have a force-dependent activity, subclass 1 myosins are not. Two subclass 2 myosins (Rat Myo1b and Mouse Myo1c) have been shown to have a high degree of force-sensitivity, but no subclass 1 myosin has yet been tested. To test the force sensitivity of AM1C, which is from subclass 1, we are using an optical trap, which allows us to apply picoNewton forces to single myosin motors.
thumb|center|170 px|Cartoon of a myosin attached to a bead that is held in an optical trap.