Pressure-Induced Changes in the Structure and Function of the Kinesin-Microtubule Complex

Abstract

Kinesin-1 is an ATP-driven molecular motor that "walks" along a microtubule by working two heads in a "hand-over-hand" fashion. The stepping motion is well-coordinated by intermolecular interactions between the kinesin head and microtubule, and is sensitively changed by applied forces. We demonstrate that hydrostatic pressure works as an inhibitory action on kinesin motility. We developed a high-pressure microscope that enables the application of hydrostatic pressures of up to 200 MPa (2000 bar). Under high-pressure conditions, taxol-stabilized microtubules were shortened from both ends at the same speed. The sliding velocity of kinesin motors was reversibly changed by pressure, and reached half-maximal value at approximately 100 MPa. The pressure-velocity relationship was very close to the force-velocity relationship of single kinesin molecules, suggesting a similar inhibitory mechanism on kinesin motility. Further analysis showed that the pressure mainly affects the stepping motion, but not the ATP binding reaction. The application of pressure is thought to enhance the structural fluctuation and/or association of water molecules with the exposed regions of the kinesin head and microtubule. These pressure-induced effects could prevent kinesin motors from completing the stepping motion.

High Hydrostatic Pressure Induces Counterclockwise to Clockwise Reversals of the Escherichia coli Flagellar Motor

“…All assays were repeated with at least three different cultures. In addition, we confirmed that the applied pressure did not significantly change the physical characters, such as temperature, viscous drag, and pH, of the solution (20,32). Figure 1a shows a schematic diagram of our high-pressure microscope (32).…”

“…Hydrostatic pressure is one of the physical stimuli that characterize the environment of microorganisms (16,17), and the pressure-induced changes could be visualized by high-pressure microscopy (18)(19)(20)(21)(22). E. coli is a representative research target for studying the mechanism by which hydrostatic pressure affects bacterial physiology, such as transmembrane transport (23,24), protein and nucleic acid synthesis (25), enzymatic function (26), cell division (22,27,28), and growth (27)(28)(29).…”

Pressure effects on lipid membrane structure and dynamics

“…There have been exciting recent developments in design and use of high pressure optical microscopy systems, allowing bright field (Frey et al, 2006;Reck et al, 1998), polarizing (Reck et al, 1998;Salmon, 1975;Salmon and Ellis, 1975) and fluorescence (Nicolini et al, 2006a;Nishiyama et al, 2009;Vass et al, 2010) microscopy, at pressures as high as 700 MPa (Vass et al, 2010). A number of these cells have again been based on similar design principles to the soft matter SAXS cells described above with the pressure being held by rubber or metal o-ring type seals (Reck et al, 1998).…”

Comparison of active and passive forces of the pelvic floor muscles in women with and without stress urinary incontinence

“…According to Nishiyama et al 25 pressure is directly proportional to strength even thought they are different measures. Many studies 11,26,27 with pressure manometers, also known as perineometers, compared the PFM pressure of continent and incontinent women and found a higher pressure in continent women corroborating with the results of the PFM anteroposterior active strength obtained in the present study.…”