Cell Organisation and Movement

Flashcards on Cell Migration

Filopodia

Protrude from the leading edge of motile cells and contain tight bundles of actin filaments formed by actin regulatory proteins called formins.

Lamellipodium

The leading edge, a highly dynamic region containing complex network of branched actin filaments formed by the activity of the Arp2/3 complex.

Stress fibers

Contractile microfilaments that attach to the substratum of the cell through specialised regions called focal adhesions or focal contacts.

Focal adhesions

Specialized regions where stress fibers attach to the substratum of the cell.

Integrins

The membrane proteins involved in attachments that link extracellular matrix interactions to the actin cytoskeleton.

Myosins

Actin binding motor proteins that generate contractile force in stress fibres.

TGF-b

A protein released from sites of damage to accelerate the healing process; stimulates immune cells to migrate to the site of injury.

PDGF (platelet derived growth factor)

Growth factor secreted by platelets that attracts fibroblasts and epithelial cells to enter a wound and repair it.

Cdc42, Rac, and Rho

Small GTPases of the Ras superfamily that regulate different rearrangements of the cytoskeleton in response to receptor stimulation and contribute to wound healing.

GEF (Guanine nucleotide exchange factor)

Activates Rho proteins by catalysing transfer of GTP for GDP, causing them to localise to the membrane.

GAP (GTPase activating protein)

Returns Rho protein to the cytoplasm from the active state.

Wound healing assay

Cells are grown to a monolayer on a petri dish and scratched to simulate a wound. Cells on the edge sense the loss of their neighbours and in response to components of the extracellular matrix now exposed on the dish move to fill up the area.

LPA (lysophosphatidic acid)

Released from activated platelets and is a well known activator of Rho.

WAVE

An Arp2/3 activator similar to WASp.

Metastasis

The spread of cancer cells from a primary tumor to a distant site.