Cell signalling:Notch

Question 1

What do all cells in the notch-delta signalling pathway express?

Answer 1

-All cells express Notch and Delta

Question 2

What is the notch-delta signalling pathway used to make?

Answer 2

-This pathway is used to make 2 types of cells from a homogenous field of cells

Question 3

During what process does the notch-delta signalling pathway occur?

Answer 3

-This process happens during neurogenesis in the embryo

Question 4

What is delta?

Answer 4

-Delta is the receptor for notch

Question 5

What does notch repress?

Answer 5

-Notch represses activity of delta

Question 6

What will cells with slightly higher levels of delta do, why so and what is this process called?

Answer 6

• Cells with slightly higher levels of delta will activate more notch and lead to repression of delta in adjacent cells. This is because a small difference is amplified.
  - This process is called lateral inhibition

Question 7

What happens a ligand binds to the notch receptor?

Answer 7

-Ligandproteins binding to the extracellular domain of Notch and induce proteolytic cleavage and release of the intracellular domain, which enters thecell nucleusto modifygene expression.

Question 8

What would no notch activity result in the process of neurogenesis?

Answer 8

• No notch activity means no lateral inhibition

- All cells in that field will differentiate as neurons.

Question 9

What is the structure of notch?

Answer 9

The notch receptor is a single-passtransmembrane receptorprotein. It is ahetero-oligomercomposed of a largeextracellularportion, which associates in acalcium-dependent,non-covalentinteraction with a smaller piece of the notch protein composed of a short extracellular region, a single transmembrane-pass, and a smallintracellularregion.