University:
The Pennsylvania State University
Course:
BIOL 230W | Cellular Biology
Academic year:

2023
Views:

373

Pages:

2
Author:

Sarah Landeck

BIOL 230W - Week 12 Cell Motility — Cells gain motility during wound repair (release chemoattractants) — Fibroblasts move to the wound (gain motility from chemoattractants), which rebuilds extracellular matrix — signals motility of epithelial cells to sca olding via interactions with bronectin and integrin —> Called epithelial-mesenchymal transition (gain motility) — 3 types of cell junctions = occluding (tight), anchoring (desmosomes), gap —> Anchoring junctions use cadherin, form desmosome (made of cadherins that interact with each other) - epithelial cells, E-cadherins interact with each other. Mesenchymal cells, N-cadherins interact with the ECM, promote motility —> occluding junctions seal o space between cells, help regulate what comes into cell Cell Motility pt 2 — Chemotaxis: cell movement in response to an environmental cue —> signals are chemical and can either be attraction or repulsion — Amoeboid Motility: utilization of cytoskeleton (polymer network) to move —> the 2 major components of the cytoskeleton are microtubules and actin — Actin forms a polymer of itself - monomer is G-actin, polymer is F-actin — Steps of amoeboid movement = self-polarization, protrusion, adhesion, contraction, and detachment/tail retraction —> In self-polarization, leading edge/trailing edge made by signaling molecules —> actin is located closer to the edge of the cell, microtubules closer to middle ff ff fi —> when a signal is detected, microtubules destabilize, and migrate to leading — increased actin on the leading edge stimulates protrusion formation —> Filopodium are nger-like, lamellipodium are at — Focal Adhesion: stable interaction between ECM and cell ( lopodia) fi fl fi fi — During contraction, stress bers are formed w myosin along them, motors