CellSig10 - 18 Flashcards
How many families of RTKs are there?
16
Characterise RTKs
EC domains vary greatly, IC have kinase activity, 1TM with a lack of structure
Outline canonical RTK activation
Ligand dimerises and facilitates the dimerisation of receptors > IC kinase domains phosphorylate each other > stabilisation, and creation of docking sites
How do we analyze RTK signalling?
Mutate one version - this poisons endogenous receptor, which interrupts function; create homodimerisation domain that forces constiuent activity
Characterise the role and structure of heparan sulphate proteoglycans
Protein core,polyanionic (negative), long heparan (sugar) chains, each sugar can be modified in different ways > possible ‘code’ that creates binding sites?
What broader family are HSPGs part of?
GAGs - Glycosoaminoglycans
What are HSPGs integral to?
FGF signalling - they first form oligomers with HSPGs
3 proteins that bind RTKs
PI3K, GAP, PLC-g
What often form between cysteines and what is their function?
Sulphide bridge - often hold EC proteins together
What transporter takes up glucose?
GLUT4 proteins
How are GLUT4 receptors involved in the insulin pathway?
They are held in IC vesicles that fuse immediately after insulin binding, causing a massive uptake of glucose from the bloodstream
What does insulin binding result in?
Autophosphrylation and ligand independence
What is IRS?
Insulin receptor substrate
What does IRS contain?
PTB - phosphotyrosine binding domain
What does IRS do?
Acts a docking site for many other proteins, such as GRB2 of the RAS pathway
