1.36 - Extracellular matrix, cell adhesions and junctions 27/52

Give an example of a syndrome that arises due to deficiency of ECM protien?

Marfan sydrome - reduced amount of fibrillin-1, or an alter in the structure of stability of fibrillin-1

What does the ECM contain?

Macromolecules of proteins and polysaccharides

What are the proteins found in the ECM /

fibrous proteins - E.g. Type IV collagen Fibrillar collagen Glycoproteins - E.g. Laminin Nidogen Fibronectin

What are the polysaccharides found in the ECM?

Glycosaminoglycans and proteoglycans - E.g: Hyaluronan perlecan DecorinAggrecan

What is the function of the ECM?

Fills intercellular spaceDetermines mechanical and other physical properties of tissue

What are the cells of connective tissue that produce ECM?

FIbroblasts - most of connective tissues CHondroblasts - cartilage Osteoblasts - bone

What are 2 types of fibrous proteins of ECM and where are they found?

Collagens - found in skin, tendon and bones Elastin - found in arteries

What are 2 examples of glycoproteins; and where are they found?

Fibronectin - found on fibroblast cell membrane - binds to collagen Laminin - forms part of the basement memrbane

Describe the composition of a GAG?

Disaccharide subunits: (amino sugar + Uronic acid) unbranched polysaccharide

Give examples of glycosaminoglycans?

1. Hylaruonan (Hyaluronic aicd) 2. Chondroitin sulfate3. Dermatan sulfate4. Keratan sulfate5. Heperan sulfate

What are proteoglycans?

Core protein with attached polysaccharide fibres

Give 3 examples of proteogylcans and where they can be found?

Decorin (common in connective tissues_ Aggrecan (cartilage) Perlecan (basal lamina)

What are cell junctions?

Protein structures connecting the cell with another cell or the cell with ECM

What are the functions of cell junctions?

Mechanical connection of cells Attachment of cells to ECM Communication between cells

What are the different types of cell junctions?

Occluding cell junctionsAnchoring cell junctions Communicating cell junctions

What are occluding cell junctions; what are they made of?

AKA Tight junctionsSeal the space between cells Made of Claudins and ocludins

What are the function of anchoring cell junctions?

Interaction cell-cell Interaction cell-ECM

What are the 2 types of anchoring cell junctions?

Junctions bound to; 1. Microfilaments2. Intermediate filaments