Cell matrix 2020 Flashcards
Provide structural integrity for bone and cartilage; also major component of basement membranes
Collagens
Type I collagen is found _____
almost everywhere
Type II collagen is found _____
almost exclusively in cartilage
Type IV is best remembered for its role ______
in basement membranes (basal lamina).
Types ___ and ____ are fibril-forming collagens, while Type _____is a network
I and II fibril. IV is a network
Type XVIII collagen is important because it is _____, and contains an _______ that is cleaved from Type XVIII, called endostatin
it is blood vessel specific, and contains internal peptide sequences
________ is a powerful anti-angiogenesis protein
Endostatin
Ubiquitous; provide hydration and structural support for cells and cartilage (“shock absorbers”). Act as reservoirs for growth factors, and cytokines.
Proteoglycans and hyaluronan
_______ are secreted and bind tightly to the cell surface through their interactions with integrins. Help attach cells to each other and to the ECM via multiple binding sites for cells, proteoglycans, and collagen
Matricellular proteins
Best known examples for matricellular proteins (3) and where each is found
- Fibronectin (found in connective tissue/ mesychymal matrices)
- laminin (found in basement membranes).
- CCN
Via their interactions with the integrins and growth factors, _________ are connected to the cytoskeleton and signaling pathways within cells, and thus help regulate important cell functions like proliferation, motility, and differentiation.
matricellular proteins
Receptors for fibronectin, laminins, CCN proteins as well as other molecules; often connect to cell signaling and cytoskeletal machinery via tightly complexed proteins on cytoplasmic side of membranes
Integrins
_________is the prototype integrin mutation pathology
Glanzmann’s Thrombasthenia
Remember that leukocyte ”rolling” along the vascular endothelium is due to weak “on-off” interactions between _______ (a matricellular protein) on the endothelial cell and a _________ on the leukocyte
P-selecting on endothelial cell
carbohydrate ligand leukocyte
Process of leukocyte adhesion to endothelial cell
Edonthelial cells express Platelet Activating Factor (PAF), –>binds to the PAF receptor on the leukocyte–> activates a specific integrin that binds tightly to ICAM-1 on Endothelial Cell membrane–>causes leukocyte to “stick”–>initiates extravasation of the leukocyte (migration between EC to enter the inflamed area).
