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19 Cards in this Set
- Front
- Back
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When talking about ground substances, what form of proteoglycan should we be familiar with?
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perlecan
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When talking about multiadhesive matrix proteins, what two should we be familiar with?
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laminin and fibronectin.
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glycosaminoglycans (GAGs) - are they charged? What function does/doesn't this allow?
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Yes - highly negative charge, means they absorb water really easily.
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How are GAG's and proteoglycans related?
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GAG's bound to a protein core are proteoglycans.
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What 3 proteoglycans should we know about, where are they located, and what do they do?
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Aggrecan - in cartilage = mechanical support with hyaluronic acid + TGFb
Decorin = all over ECM, binds to type 1 collagen Perlican = in basal lamina - structural/filtering |
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Where is the proteoglycan Decorin found?
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All throughout the extracellular matrix. Keeps collagen from growing too large.
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Where is the proteoglycan Perlecan found?
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Basal lamina, offers structural support.
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What are multiadhesive matrix proteins, and what 2 should we be familiar with?
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they're in the matrix, hold cells in place. Fibronectin - most abundant in ECM
Laminin - Big part of basal lamina, role in neuronal development. |
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Tell me about fibronectin - what's its basic structure, and where do receptors bind?
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It's 2 nearly identical long proteins, connected by disulfide bonds. RGD domain in the middle recognized by fibronectin receptors. Has binding sites for lots of things - cells, fibrin, collagen, heparin
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Tell me about laminin - how many chains make it up?
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Laminin has 3 chains - alpha/beta/gamma. Can bind neurites, carbs, type 4 collagen.
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In muscular dystrophy, what does dystrophyn link to outside the cell?
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laminin
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There are inter-membrane proteins that help bind cells to each other and to the matrix. What are the homophilic ones?
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Homophilic = Cadherins (in desmosomes, bind two cells together in dev).
IgCam's (or cell-adhesion molecules) - look like IgG w/ beta sandwiches, but not. Important in neurons. |
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What are the heterophilic transmembrane cell adhesion proteins?
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Integrins - have alpha/beta subunit, attach to things like fibronectin.
Selectins - bind carbs. |
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Leukocyte extravasation (getting b/t epithelial cells to fight infection) - what's important here?
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Damaged epithelia will express selectin on their surfaces - will bind to carbs on passing leykocytes. facilitate binding of integrins, ten they extravasation through to the infection.
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Integrin specificity - how is it dictated? what are some possible binding targets?
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it all depends on which alpha and which beta subunits work together. Can bind RGD, laminin, collagen, leukocytes.
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Integrin signaling - it has a couple possible classes of signaling. what are they?
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ERK1/2 - helps growth
Rac/Rho/CDC42 g proteins - reorganize, help movement. |
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How are integrins usually expressed on the cell surface during quaiscent existence?
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Inactive - can be activated by growth signals, then allow the communication of IP3, Erk1/2, other growth-enhancing elements.
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List 3 pathways that integrins transmit:
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ERK1/2 (extracellular regulated kinases)
Cell mobility (Rac/CDC42/Rho) PIP3 (and so, PKB) |
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Cadherins and IgCams - when/where are they important?
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Cadherins are in DESMOSOMES and are important during development.
IgCams: important in neuronal development. |
