There are a number of protein systems involved in motility that are not based on actin and myosin. Several of these systems are described below:
Microtubules
Microtubules are made up of helical
arrays of two subunits, 
and 
tubulin, both of which are 55 kDa in size. The helical array is made up
of 13 columns.
Tubulin can be purified by cooling microtubules to 4oC, this
results in
their dissociation into dimers (). Warming of this solution to
physiological temp (37 C) facilitates polymerization:
() dimers + GTP -------> associate (GTP
is hydrolyzed, but GDP + P
remain bound)
The microtubules that form have vectorality; they grow mostly at the "+" end
Eukaryotic Cilia and Flagella
The filament structure of eukaryotic cilia and flagella is based on a 9 + 2 array of microtubules above.
The 9 outer fibers are actually two fused columns; the A fiber has 13 rows of tubulin, and the B fiber has 10-11 rows.
Additional proteins are also found in cilia and flagella including nexin, which connects the fused columns along the circumference, dynein, which has two "side arms" and is associated with the outer double columns, and a radial spoke protein that extends from to the outer double columns to the center two columns of tubulin.
Eukaryotic flagella move by bending; sliding occurs between columns of tubulin based on the movement of dynein arms (contrast this mode of creating movement with bacterial flagella below).
Axonal Transport:
Nerve cells have a particularly difficult logistical problem; the nucleus, which is located in the cell body, is a great distance from the nerve ending. The mRNA for protein synthesis is transcribed in the nucleus and many proteins which are required for maintenance of nerve endings must be transported from the cell body to the endings. Nerve cells transport proteins and some organelles move down the axon to the nerve ending via microtubules, very much like a railroad with small cars.
Vincristine and vinblastine are members of the family of vinca alkaloids. Biochemists have known for some time that they break up microtubules, and that they also prevent axonal transport.
This transport can be detected by injecting radiolabelled amino acids into the cell body and monitoring the movement of the proteins synthesized from these amino acids, some of which can move along the microtubules as rapidly as 40 cm/day.
The vesicles involved in this transport have little feet made of dynein and kinesin. Dynein moves down the microtubules toward the "-" end of that molecule, and kinesin moves along the microtubules toward the "+" end. Both of these proteins produce movement by hydrolyzing ATP.
Mitosis
During cell division, each daughter cell receives one of the sister chromatids. This movement involves the mitotic spindle, which is composed mainly of microtubules that extend from pole to pole.
ATP is required for the movement of these filaments; the exact mechanism of this movement is not known.
Bacterial Flagellum
A bacterial flagellum is a fiber made of a fibrous protein called flagellin. It is anchored to cell via a hook structure, a bearing , a rod, an S (stator) ring, and an M (motor) ring.
This structure rotates at about 60 revolutions/second to produce motion, and uses approximately 1,000 protons per turn. It revolves in one of two directions, clockwise or counterclockwise.
Counterclockwise motion produces running (swimming) and clockwise motion produces tumbling. Chemotaxis, the process of sensing molecules in the environment, determines how much of each type of flagellar motion occurs and when.
The sequence of events in chemotaxis starts with the binding of a sugar (an attractant) to a receptor, a series of phosphorylations, followed by a signal to the motor. The chemotactic system measures the concentration of a substance (sugar) at one time and compares it with the concentration at some later time. Swimming toward an attractant (sugar) permits the bacterium to move toward a supply of nutrient.
