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Cells interact with extra-cellular material and other cells to form ______.
Cell coat that is formed from carbohydrates projecting from membrane lipids and proteins.
- Glycocalyx. COVERS MEMBRANE.
DEFINE extracellular matrix (ECM):
Organized network beyond the plasma membrane
THE GLYCOCALYX IS FROMED BY WHAT?
Cell coat that is formed from carbohydrates projecting from membrane lipids and proteins
WHAT Underlies epithelia and surrounds muscle and fat cells?
- BASEMENT MEMBRANE
- (BASAL LAMINA)
NAME 4 FUNCTIONS OF BASAL LAMINA
- Maintains epithelial polarity
- Assists in cell migration
- Barrier to macromolecules
- Gives connective tissues their identifiable properties
THE ECM IN ANIMALS CAN BE COMPARED TO WHAT IN PLANTS?
IT'S LIKE A CELL WALL. ITS SOMEWHAT OF A LOSE MATRIX.
IF YOU WANTED TO STAIN THE GLYCOCALYX TO VIEW UNDER AN EM, WHAT WOULD YOU USE?
IRON PROTEIN FERRITIN
"OUTSIDE" LUNGS, MOUTH, GI TRACK, ECT.
COLLAGEN FIBERS CAN BEND, BUT CANT STRECH
THE RETICULAR FIBERS OF THE DERMIS CAN RETAIN WATER FOR AIDING IN ELASTICITY.
OVER TIME COLLAGENS TURN INTO WHAT
RETICULAR FIBERS. LOSE ABILITY TO STRETCH
- Family of glycoproteins only in ECM.
- Collagen is a trimer- three polypeptide chains throughout animal kingdom.
- 20 DIFFERENT TYPES. EX: Fibrillar collagen = high tensile strength
COLLAGEN IS CONSTRUCTED OUT OF WHAT PROTEIN CONFIRMATION.
TRIPLE HELIX ROD WRAPPED TOGTHER.
Most abundant protein in human body at 25%
Produced by fibroblasts, smooth muscle cells and epithelial cells?
CELL CAN FORM A NETWORK AND MAINTAIN IT HOW. WHAT COULD YOU USE?
COLLAGEN. THINK STRUCTURAL NETWORK.
DEFFINE Proteoglycans (PGs)
- Protein-polysaccharide complexes with a core protein attached to glycosaminoglycan (GAG) chains
- Repeated disaccharide structure
- Negative charge attract cations and HELP KEEP H2O AROUND CELL.
- REMEMBER THAT THEY CONTAIN ALCOHOL, HYDRPHILLIC.
Forms a porous hydrated gel IN THE ECM
- Proteoglycans REMEMET THAT ITS A TYPE OF CARTILAGE.
Molecule has the volume of a bacterial cell
Porous gel allows for ECM to remain hydrated
Resists crushing & pulling forces.
WHAT THE HELL AM I?
- Proteoglycan complex: Cartilage matrix material.
- THINK PACKING PEANUTS.
_________ & __________ and other proteins bind collagen or PGs, or bind cells to the ECM
Fibronectin AND laminin
- linear array of building block polypeptides joined by disulfate bridges.
Composed of 30 independently folding modules
Found in blood clotting cascade and as membrane receptors
Evolutionary array of 5 or 6 functional domains from various sources.
WHAT THE HELL AM I?
Binding domains connect to integrins involved in cell movement and signal transduction. NOT CELL BOUND, FLOATING
- Fibronectin. THINK PURPLE CLOTHES PINS.
WHAT THE HELL IS THIS?
WHAT IS RGD COMPED OF?
- RGD = ARG - GLY - ASP
- THIS HELPS THE CELL SEE THE FIBRONECTIN AND CAUSES THE CELL TO RESPOND TO IT.
WHAT THE HELL IS GOING ON HERE?
- REMEMBER THE Fn HAS RGD, SIGNAL CELL TO BIND TO IT.
- fibronectin coating for cell guidance
- White Fn boundaries areas
- Cells moving out from areas (arrows) loose
- adhesion/migration ability and ball up.
NAME 2 FUNCTIONS OF FIBERNECTIN
STRUCTURE AND IMGRATION
Progenitors of lymphoid cells go to.....WHERE?
- liver, bone marrow, thymus and lymph nodes and spleen.
- REMEMBER FIBERNECTIN FORMS PATHWAYS.
PRIMORDIAL GERM CELLS PGCs migrate from yolk sac to WHERE?
- GONAD SITE. REMEMBER FIBERNECTIN FORMS PATHWAYS.
neural crest become WHAT?
- Pigment skin cells, sympathetic ganglia, adrenal medula skull cartilage. BLUE. REMEMBER FIBERNECTIN FORMS PATHWAYS.
Most important family of receptors functioning in attachment
- macromolecular complex formed by two, usually non-covalently bound, macromolecules like proteins or nucleic acids. It is a quaternary structure of a protein.
- THINK INTEGRINS
Adhere cells to substratum and transmit signals from environment to cell interior
Large extracellular domains have Mg+ or Ca+ -dependent ligand-binding sites specific for arg-gly-asp (RGD) sequences
IF YOU WANT TO INHIBIT INTEGRINS WHAT COULD YOU USE?
- RGD containing drugs or toxins inhibit normal integrin function.
- BLOCKS RECEPTORS
Integrin extracellular protein receptor domains..NAME 3 METALS.
- Ca2+, Mg2+, and/or Mn2+.
- NOTICE ALL 2+ METALS
WHEN IS AN INTEGRIN ACTIVE?
- UPRIGHT CONFIRMATION.
- WHEN IT'S INACTIVE, IT'S KNOWN AS BENT LEG CONFORMATION.
NAME A PROTEIN TIN THE CELL THAT BINDS TO A INTEGRIN AND CHANGES IT CONFORMATION. WHERE SPECIFICALLY DOES IT BIND TO?
- TALIN. BIND TO THE BETA. NOTICE HOW WIDE IT OPENS.
glycoprotein of the extracellular matrix that binds to membrane-spanning receptor proteins called integrins. In addition to integrins, fibronectin also binds extracellular matrix components such as collagen, fibrin and heparan sulfate proteoglycans (e.g. syndecans).Fibronectin exists as a protein dimer, consisting of two nearly identical monomers linked by a pair of disulfide bonds.
Blood clots form when platelets adhere to one another through ________ bridges that bind platelet ________.
- fibronectin bridges & platelet intergrin.
A PATIENT HAS A HIGH CLOT RISK. WHAT CAN BE ONE SOLUTION?
- Non-peptide analogs used to treat patients with high clot risk.
____ _____ cells form stable attachments on contact with substrates, flatten over time
- In vitro
- Dynamic structures that can be rapidly disassembled if mitosis is triggered
- Integrin heavy clusters at attachment points
- Start as ball and then flatten out. LEGS ATTACHED, CENTER ISN'T.
IF YOU HAVE A LARGE AMOUNT OF VINVULIN IN THE CELL WHAT WILL BIND ON THE OUTSIDE?
WHAT ABOUT TALIN?
- BOTH ATTACH TO B SUBUNIT.
Focal adhesions are sites where cells adhere to their substratum
WHERE IS THE ACTIN? WHERE ARE THE INTEGRNS?
- Grey-green= actin
- Red= integrins
In vivo tightest cell-substrate connections are mediated by __________.
- IN VIVO...IN LIVING
HOW DO EPITHELIAL CELLS ATTACH TO BASEMENT MEMBRANES?
WHAT THE FUCK IS PAXILLIN?
Interactions Between Cells:___________ bind to specific carbohydrates on surfaces of cells
____________ mediate interactions between circulating leukocytes and vessel walls
NAME THE 3 TYPES OF SELECTINS
- E (endothelial cells), P (platelets) and L (Leucocytes)
SELECTINS DEPEND ON WHAT MINERIAL FOR BINDING?
If you dissociate embyonic cells and remix them, they sort with like types...HOW DOES THIS HAPPEN?
Surface interactions allow for this. Selectins, IgSF, Integrins and Cadherins contribute to organization patterns
GIVE AN EXAMPLE OF A SELECTIN ON RBC
THE A,B,O ANTIGENS.
WHAT THE HELL DOES " OLIGO-" MEAN?
- SHORT. HAVING ONLY A FEW.
- EX: An oligonucleotide (from Greek prefix oligo-, "having few, having little") is a short nucleic acid polymer, typically with fifty or fewer bases.
WHAT COULD BE THE 2 MAIN WAY TO HAVE A MANFUNCTION IN A SELECTIN?
- CHANGE ITS SHAPE, COULD BIND ANYMORE.
- CHANGE CAROXYL/HYDROXYL GROUPS ON BINDING SUGARS.
immumoglobulin superfamily (IgSF) NAME 3 AND THEIR FUNCTION
- NCAM (neural), VCAM (vascular), and L1
- IgSF proteins mediate adhesion between non-immune cells directly or through integrins.
- ALSO Found in invertebrates (no immune system).
Most immumoglobulin superfamily (IgSF) proteins are involved in immunity...WHAT 2 THINGS DO THEY FUNCTION LIKE?
Antibody and T-cell receptor function
word, phrase, number, or other sequence of units that may be read the same way in either direction
THE Ig DOMAINS OF THE IgSF ARE MADE OF WHAT?
Made of b-sheets packed face to face
THE IgSF VCAM IS FOUND WHERE?
WHAT IS ONE WAY THE IgSF CELLS DON'T STICK TO GOOD HEALTHY CELLS?
MOST ARE CALCIUM INDEPENDANT CELL-CELL ADHESIONS. SPECIFICY WITH CALCIUM.
WHAT IS AT THE END OF EACH OF THE END OF THE Ig DOMAINS?
- Glycoproteins mediating Ca+ -dependent cell adhesion that join cells of similar type.
- Catenins tether the cadherins to the cytoskeleton and transmit info to the cytoplasm.
- Associate laterally forming dimers bridged by Ca+ in a “cell adhesion zipper”
CADHERINS DEAL WITH WHAT MINERAL
WHAT DO CADHERINS DO?
FUNCTION IS CELL ADHESION. HELP CELLS FORM BONDS AND CONSTRUCT A TISSUE FORMATION.
________ tether the cadherins to the cytoskeleton and transmit info to the cytoplasm
_________ associate laterally forming dimers bridged by Ca+ in a “cell adhesion zipper."
Cadherins in epithelial-mesenchymal transformation, WHAT'S THE FUNCTION?
- N-Cadherin production correllated to structure development.
- Cell migration from ectoderm (outer) to mesenchymal (inner)position forming somites.
DESMOSOME/HEMIDESOMES...WHERE DO YOU FIND EACH OF THEM?`
- ADHERENS JUNCTIONS.
- Anchor cells to other cells.
Catenins & cadherins. WHAT ARE THEIR FUNCTIONS.
- Catenins tether the cadherins to the cytoskeleton.
- Cadherins Glycoproteins mediating Ca+ -dependent cell adhesion that join cells of similar type
_______ ______ in epithelia forms a belt around cell’s apical surface. think cell to cell contact.
Cell-to-cell contact in adherens junctions are cemented by Ca+-dependent linkages. why?
- Extracellular domains of cadherin molecules.
- REMEMBER WHEN YOU SEE CADHEREIN OR CATENINS THINK CALCIUM