Amoeboid movement

[1] It is a crawling-like type of movement accomplished by protrusion of cytoplasm of the cell involving the formation of pseudopodia ("false-feet") and posterior uropods.

Sarcomas, or cancers arising from connective tissue cells, are particularly adept at amoeboid movement, thus leading to their high rate of metastasis.

[5][6] Polarity gives cells distinct leading and lagging edges through the shifting of proteins selectively to the poles, and may play an important role in eukaryotic chemotaxis.

[7][8] Crawling is one form of amoeboid movement which starts when an extension of the moving cell (pseudopod) binds tightly to the surface.

[10][12] The protoplasm of an amoeba is made up of an outer layer termed the ectoplasm which surrounds an inner portion called the endoplasm.

[14] It is proposed that microdomains weave the texture of cytoskeleton and their interactions mark the location for formation of new adhesion sites.

The interaction of myosin with the actin network then generates membrane retraction/ruffling, retrograde flow, and contractile forces for forward motion.

In addition to actin polymerization, microtubules may also play an important role in cell migration where the formation of lamellipodia is involved.

One experiment showed that although microtubules are not required for actin polymerization to create lamellipodial extensions, they are needed in order to afford cellular movement.

This mode of amoeboid movement requires that myosin II play a role in generating the hydrostatic pressure that causes the bleb to extend.

[16]  This is different from actin-driven locomotion where the protrusion created is by the actin polymerizing while remaining attached to the actomyosin cortex and physically pushing against the cell's barrier.

[17] It has also been observed that the blebs formed by motile cells undergo a roughly uniform life cycle that lasts approximately one minute.