White Cell Communication 2

Question 1

GPCR can attach to G-alpha(q) or G-alpha(o). Instead of the downstream effector being adenylyl cyclase, these proteins have this as the effector, ___.

Answer 1

phospholipase C

Question 2

Phospholipase C cleaves ___ into __ and __.

Answer 2

PIP2 into IP3 and DAG.

Question 3

IP3 triggers release of __ from the ER, which also acts as a second messenger.

DAG and calcium both bind to ___ ___ _. This causes a conformational change in that protein, activating it to ___ a variety of membrane and cytoplasmic substrates.

Answer 3

Calcium.

Protein Kinase C (PKC).

phosphorylate.

Question 4

RTK stands for ___. They play an important role in signal transduction and mediate __ factor signals.

They phosphorlyate proteins on what amino acid residue?

Answer 4

Receptor Tyrosine Kinase.

growth.

Tyrosine.

Question 5

Some examples of growth factors are EGF, PDGF, NGF, FGF, and IGF-1. What do the acronyms stand for?

They all have a tyrosine kinase domain, located on which side of the cell membrane?

Answer 5

EGF = epidermal growth factor.
PDGF = platelet derived growth factor.
NGF = nerve growth factor.
FGF = fibroblast growth factor
IGF-1 = insulin-like growth factor

cytoplasmic side.

Question 6

Protein kinases add a __ to proteins, activating them. Protein phosphateses then do what to the active protein?

Answer 6

phosphate.

Phosphateses remove the phosphate group from the active protein, inactivating it.

Question 7

__ was the first discovered human oncogene

Answer 7

Ras.

Question 8

Rather than using RTKs, a more direct route for impacting transcription is by using ___ receptors.

Answer 8

JAK-STAT

Question 9

Hepcidin utilizes serine-threonine ___ signaling. Erythropoeitin utilizes ___ signaling.

Answer 9

R-smad/Co-smad.

JAK-STAT

Question 10

Briefly describe JAK-STAT signaling.

Answer 10

ligand binds, then JAK binds to protein. JAKs phosphorylate each other and the receptor. Receptor binds and phosphorylates STATs. STATs separate from receptor, dimerize, enter nucleus and initiate gene transcription.

Question 11

This protein, ___, made in the liver and acting on the intestine, internalizes ferroportin, controlling levels of iron in blood serum.

If serum iron levels are down, is hepcidin expression increased or decreased to compensate?

Answer 11

hepcidin.

low serum iron results in decreased hepcidin expression in the liver because we want ferroportin to be active, transporting iron out of the cell and into the blood.