Cell Adhesion and Migration
What drives Plasma Membrane Protrusion?
Actin Polymerization
what is attachment?
Actin cytoskeleton connects across the plasma memebrane to the substratum (ECM)
What are 6nm diameter, actin subunits make up linear polymers that can shrink, elongate, and generate force?
Actin filaments
What is protrusion
Actin-rich structures are pushed out at the front of the cell
Whats Serves as a nucleation sites to initiate the assembly of new filaments?
Arp2/3 proteins (actin related proteins)
What are Cells that grow only locally and cannot spread by invasion or metastasis Called?
Benign Tumor
What provides traction between cell and ECM?
Integrin attachment
What are critical transmembrane receptors that regulate cell to cell and cell to ECM connections called?
Integrins
What are 10 nanometers in diameter, more stable than actin filaments. Like actin filaments, they function in the maintenance of cell-shape called?
Intermediate filaments
Motor Protiens
Provides the force to move the cell
What is now appreciated to be a dynamic entity with a complex role in regulating cellular behavior?
ECM function
What Gives Tissues Their Elasticity?
Elastin
What is A process characterized by loss of cell adhesion, repression of cadherin expression and increased cell motility
Epithelial-mesenchymal transition or transformation (EMT)
Cells either float through our vessels, are attached to other cells, and/or are bound to or moving on the what?
Extracellular matrix (ECM).
Collagen is predominately generated by what?
Fibroblast cells
An Extracellular Protein That Helps Cells Attach to the Matrix
Fibronectin
What are collagen, elastin, fibronectin, and laminin, which have both adhesive and structural functions.
Fibrous proteins
What is Formed by migrating growth cones and some types of fibroblasts, are essentially one dimensional. They contain a core of long, bundled actin filaments.
Filopodia
What intersect at integrins and the cytoskelton?
Focal adhesions
What is Herapin?
Glycosaminoglycan
These are usually found covalently linked to protein in the form of proteoglycans, and (2) fibrous proteins
Glycosaminoglycans (GAGs),
What enzyme degrades hyaluronan?
Hyaluronidase
What do Glycosaminoglycans form?
Hydrogels
What is Formed by epithelial cells and fibroblasts, as well as by some neurons, are two-dimensional, sheet-like structures.
Lamellipodia
What does Actin Polymerization extend?
Llamellipodium, and new attachments occur at focal adhesions
Besides key degradation enzymes, where else is the matrix engulfed and destroyed?
Lysosomes
what are Cells that invade neighboring tissues, enter blood vessels, and metastasize to different sites called?
Mailgnanat
What is the trade name for a gelatinous protein mixture secreted by Engelbreth-Holm-Swarm (EHS)mouse sarcoma cells?
Matrigel
This Proteases , depend on bound Ca2+ ir Zn2+ for activity, and are secreted by cells in ECM for targeted opening of the matrix
Matrix Metalloproteases
What Demonstrates high expression of proteases that can degrade the ECM
Metastatic Cancer Cells
What are 23 nm in diameter hollow cylinders most commonly comprised of polymers of alpha and beta tubulin called?
Microtubules
What proples cell body forward?
Myosin contraction
What collagen type is basal lamina?
Network-Forming
What happens when actin polymerization pushes out the membrane?
New focal adhesions occur from proteins within the membrane and the ECM.
Cofilin
Preferentially binds to ADP-actin, so it remains bound to actin monomers following filament disassembly and sequesters them in the ADP-bound form.
What Can Reverse the effect of cofilin and stimulate the incorporation of actin monomers into filaments (needs nucleation), and acts by stimulating the exchange of bound ADP for ATP, resulting in the formation of ATP-actin monomers.
Profiling
What are 3 distinct cell crawling components?
Protrusion, Attachment, Traction
What is Formed by amoebae and neutrophils, are stubby three- dimensional projections filled with an actin-filament gel.
Pseudopodia
What provides mechanical support, determines cell shape, and allows the cell surface to move, thereby enabling cells to migrate, engulf and release particles, and divide?
The actin network
What is traction?
The bulk of the trailing cytoplasm is drawn forward
What is Shrinking at one end and elongation at another end of a filament causes net movement of the strand between the ends called?
Treadmilling
When do cells of saccharomyces cerevisiae become polarized?
When treated with mating factor from cells of the opposite mating type
What does ECM function have influence in?
cell signaling, attachment, development, migration, proliferation, shape, and ultimately function
What are found on the outside of cells within the ECM?
fibronectin fibrils
What is the thin sheet, "pod" - foot) is an actin projection on the mobile ("leading") edge of a cell called?
lamellipodium
Cell crawling involves 3 distinct components
protrusion, attachment, traction
Intermediate filaments also serve as what?
structural components of the nuclear lamina and to anchor organelles within the cell
What can increase MMP production or stimulate cells in the neighborhood?
Cancer Cells
What is an essential part of embryo development, blood vessel formation, the immune response and cancer metastasis?
Cell Migration
What is spatial differences in the shape, structure, and function of cells?
Cell polarity
What promotes disassembly of filaments?
Cofilin
What is a chain is about 1000 amino acids long and arranged as a left-handed helix, with three amino acids per turn and with glycine as every third amino acid... Gly-X-Y sequences called?
Collagen
What enzyme degrades collagen?
Collagenase
The "skeleton" or cellular scaffolding within the cell's cytoplasm.
Cytoskeleton