Signaling Development

Question 1

Knocking out Smoothin from the SHH pathway will result in (decreased/increased) Gli Activation?

Answer 1

Decreased

Question 2

The co-receptors Frizzled and Arrow/Lrp link to which ligand to promote the dissociation of the destruction complex?

Answer 2

Wnt

Question 3

In regards to the Hh pathway, the Gli/Ci proteins are ____ ____, which are phosphorylated by PKA to be degraded later on.

Answer 3

Gli/Ci proteins (Gli1/2/3)

Question 4

Does Smoothin on the primary cilia and Hh/Patch in a vesicle result in activation or inactiation of the Gli proteins?

Answer 4

Activation because Smo interrupts the Phosphorylation breakdown.

Question 5

In regards to the wnt pathway, how do you degrade Beta-Catenin?

Answer 5

Through phosphorylation carried out by the DESTRUCTION COMPLEX (Axin,APC,GSK3)

Question 6

Why are SHH proteins highlly hydrophobic?

Answer 6

They require Cholesterol to be added to the (cleaved) signaling domain.

Question 7

Cuase of Smith Lemli Opitz Syndrome?

Answer 7

Too little Cholesterol (LoF of DHCR7)

Question 8

If SHH is the ligand, then _____ is the Receptor that binds the hyrophobic Hh ligands

Answer 8

Patched (Ptc)

Question 9

What is the function of the TCF protieins, in regards to Wnt pathway?

Answer 9

• They block activation when there is no Beta-Catenin to get in the way.
• They promote activation when Beta Catenin Links up with them!

Question 10

In the simplified Hh pathway, when there is no Hh, Smoothin is inhibited and cannot interrupt PKA’s function, therefore the Gli protein’s length is ____

Answer 10

Shortened and is turned off

Question 11

In regards to the wnt pathway, the PP2A is a bypass to the normal inhibition by chopping a phosphate from _____

Answer 11

Beta-Catenin