Cell Communication 2

Question 1

What does adenylyl cyclase do?

Answer 1

generates cAMP which then goes on to interact with its target protein to cause a biological response

Question 2

GPCR attaches to _____

Answer 2

G alpha q or G alpha o

Question 3

Phospholipase C cleaves a membrane protein called ______

Answer 3

PIP2

Question 4

What does PIP 2 produce?

Answer 4

IP3 and DAG 2nd messengers

Question 5

IP3 triggers release of _______ from _________

Answer 5

Ca2+; endoplasmic reticulum

Question 6

How does IP3 trigger the release of calcium?

Answer 6

by binding to an IP3 gated Ca2+ channel and triggers opening

Question 7

Both ____ and DAG bind to another protein kinase called protein _______

Answer 7

Ca2+; kinase C

Question 8

What happens after conformational change occurs in PKC?

Answer 8

it is activated

Question 9

What does PKC phosphorylate?

Answer 9

a variety of membrane and cytoplasmic substrates

Question 10

What role does receptor tyrosine kinase (RTKs) play?

Answer 10

signal transduction

Question 11

RTKs have what type of receptors?

Answer 11

enzyme linked

Question 12

RTKs are used for response to growth factors: mediated _______

Answer 12

growth factor signals

Question 13

What is EGF?

Answer 13

epidermal growth factor

Question 14

What is PDGF?

Answer 14

platelet derived growth factor

Question 15

What is NGF?

Answer 15

nerve growth factor

Question 16

What is FGF?

Answer 16

fibroblasts growth factor

Question 17

What is IGF-1?

Answer 17

insulin like growth factor 1

Question 18

What does the cytoplasmic domain of RTKs do?

Answer 18

transmit signal through tyrosine kinase domain

adds phosphate to tyrosine on proteins

Question 19

When ligands bind to the receptor tyrosine kinase, what happens?

Answer 19

conformational change
induces dimerization of two receptor monomers
autophosphorylation occurs

Question 20

When the receptor tyrosine kinase autophosphorylates the site, what does this cause?

Answer 20

the receptor to act as a scaffold or docking site to recruit other proteins to plasma membrane

Question 21

Receptor tyrosine kinase does bind to _______ protein but to proteins with domain called ________ domain, which binds to phosphotyrosine.

Answer 21

G; SH2

Question 22

What is SOS?

Answer 22

son of seven less, fruit flies have omatidia (R1-R8). When R7 is knocked out, the fly can live and not detect UV

Question 23

What is the ligand of receptor R7?

Answer 23

Boss= bride of seven less

Question 24

What are the two proteins down stream of the R7 receptor?

Answer 24

SOS and Grb2

Question 25

What is the process of JAK-STAT?

Answer 25

1. ligand binds to receptor
2. JAKs phosphorylate each other and receptor
3. Receptor binds and phosphorylates STATs
4. STATs separate from receptors, dimerize and enters nucleus to bind to DNA and cause transcription of target genes

Question 26

______ employs JAK-STAT to initiate signaling

Answer 26

erythropoietin

Question 27

What is the process of serine threonine receptor and Smad?

Answer 27

1. activated receptor binds to R-smad and phosphorylates R-smad
2. R-smad binds to Co-smad and moves into nucleus to impact transcription of target genes

Question 28

What is heredity hemochromatosis?

Answer 28

diseases with uncontrollable iron absorption

Question 29

What does DMT1 do?

Answer 29

transfers iron into intestinal cell

Question 30

What does ferroportin do?

Answer 30

iron out of intestinal cell and into blood

Question 31

What is Hepcidin?

Answer 31

25 amino acid protein made in the liver with action in the intestine, regulator of iron homeostasis

Question 32

Hepicidin binds to _____ which causes internalization of protein which is destroyed by proteolysis

Answer 32

ferroportin

Question 33

When iron replete hepicidin expression is ____ and ferroportin levels are _____

Answer 33

up; down

Question 34

What is the gene for hemochromatosis and how common is it?

Answer 34

HFE; autosomal recessive and 1/250 incidence

Question 35

What is the mutation in HFE?

Answer 35

cys 282– tyr

Question 36

If Hfe is mutated it cannot bind to _____. Which lead to what?

Answer 36

TfR2; cannot turn on hepcidin expression, no control of ferroportin activity