Microtubules motor protein activity

Microtubules motor proteins like kinesin and dynein support a wide variety of cellular functions including intracellular cargo transport, the separation of chromosomes during mitosis or the beating of cilia and flagella. Kinesin and dynein move along microtubules utilizing energy from ATP hydrolysis to produce force and power the variety of movements in which microtubules participate. SENSOCELL optical tweezers allows studying the motion and force activity of microtubules and motor proteins in classical in vitro experiments but also in unprecedented experiments inside cells.

microtubules motor protein activity with optical tweezers

Force dynamics and mechanical properties of microtubules and motor proteins

Study the mechanics and force dynamics of microtubules and kinesin and dynein motor proteins in in vitro and in vivo experiments with SENSOCELL optical tweezers. Our optical trapping platform will allow you to asses the forces generated by microtubules and their mechanical properties or measure stall forces of motor proteins along microtubules grown in in vitro confitions or even inside living cells trapping native cell structures such as lipid droplets. Study tug-of-war and cooperating phenomena when various molecular motors act on the same cargo and measure the parallel and perpendicular to the filament components of the forces exerted on the moving cargo.

Application example 1. Measurement of the stall force of kinesin motor proteins transporting vesicles along microtubules in living cells.

Application Note. Download the kinesin motor proteins application note.

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Measurement of the stall force of kinesin motor protein transporting vesicles along microtubules in living cells

In collaboration with the University of Barcelona.

Microtubules motor proteins are responsible for different fundamental biological processes inside cells. One of these functions, of vital importance for the cell survival, is the intracellular transport of vesicles and organelles along microtubules. Kinesin is the microtubule-based motor protein that performs the plus-end-directed motion. The protein generates the mechanical work required to move cargos, by means of the hydrolysis of ATP molecules. In cells, lipid droplets can be used as targets for trapping and analysis of the force of the motor proteins propelling them. The following animation shows one example of a vesicle optical trapping experiment inside a living NG108 cell while Fig.1 shows the measurement of the stall force of a kinesin motor protein transporting lipid droplets along a microtubule in a A549 cell.

optical trapping of vesicles transported by motor proteins inside a NG108 cell

Optical trapping of vesicles inside a living NG-108 cell.

Kinesin motor protein stall force measured inside cell

Fig.1 Stall force of a kinesin motor protein carrying a lipid droplet along a microtubule inside an A549 cell. Courtesy of Dr. Mario Montes and Dr. Estela Martín (University of Barcelona).

Multiple kinesin motor proteins transport: cooperation and competition

Measurement of forces inside cells allows exploring the rich interplay between multiple molecular motors simultaneously pulling on the same vesicle/organelle. Here we show an example illustrating two opposed scenarios: cooperation and competition. Measurements like those shown here are an example of the potential of SENSOCELL in the motor proteins field, which offers the possibility of measuring forces in traditionally difficult or impossible experiments.

Motor protein cargo transport along microtubules

Fig. 2 Force curves for a lipid droplet in an A549 cell pulled by multiple molecular motors in different scenarios: in cooperation and in competition. Download full application note to see the two components of the force (parallel and perpendicular to the microtubules).

Download the Full Active Motor Protein application note:

Measurement of the stall force of kinesins in living cells