Hormone Signaling Pathways 2/1 Zaidi

Question 1

What are examples of hydrophilic molecules?

What kind of receptors do they use?

Located where?

Answer 1

Histamine, serotonin, Insulin, glucagon, ACh, etc

GPCRs and RTKs

Cell surface

Question 2

What are some lipophilic signaling molecules?

What receptors do they use?

Answer 2

Steroid hormones, thyroxine, retinoids

Within the cytoplasm and nucleus

Question 3

When the cytoplasmic receptors are in inactive form, what are they complexed with?

When translocating to the nucleus, what does it bind?

Answer 3

HSP 90

Specific DNA sequence HRE

Question 4

Which medications have a longer half life aka last longer?

Answer 4

Lipophilic meds

Question 5

What are the subunits of GPCRs?

Answer 5

Alpha, beta, gamma

Question 6

What is used to activate the inactive trimeric G protein?

Answer 6

GEF

Question 7

What is used to remove the GTP from the active G protein?

Answer 7

GAP

Question 8

What triggers the Gt pathway?

What does it activate?

Answer 8

Light

cGMP

Question 9

What are the physiological responses of Epinephrine?

Answer 9

Relax bronchial and intestinal smooth m.
Contracts heart m.
INC breakdown of TAGs, glycogen
INC glycolysis in muscle

Question 10

What pathway is used when the Beta-adrenergic Epi receptor is activated?

Answer 10

Gs

Question 11

What pathway is used when the alpha-2-adrenergic Epi receptor is activated?

Answer 11

Gi

Question 12

What connects the A chain to the B chain of insulin?

How many a.a. Is the A chain and B chain?

Answer 12

Disulfide bridges, additional one in A chain

A-21
B-30

Question 13

What phospohorylates CREB in the cytosol of epinephrine signaling?

What happens next?

Answer 13

PKA

Translocates to nucleus and activates CRE which up regulates gene expression

Question 14

What pathway is used when the alpha-1-adrenergic Epi receptor is activated?

Answer 14

Gq

Question 15

How is the inactive form of insulin stored?

Active form?

Answer 15

Hexameter

Monomer

Question 16

How are the granules of insulin divided?

Answer 16

readily releasable pool (RRP) which accounts for the 1st release

Reserve pool (95%) responsible for the 2nd phase of insulin secretion, must first undergo mobilization

Question 17

What kind of receptor does insulin use?

What specific receptor?

Then what happens?

Answer 17

RTK

IRS-1

Receptor is phosphorylated

Question 18

Describe the RAS dependent pathway

Answer 18

IRS-1 -> GRB-2 -> RAS -> alters gene transcription (INC glucokinase) -> INC glucose uptake and glycogen synthesis

Question 19

Describe the RAS independent pathway

Answer 19

IRS-1 -> PI 3-kinase -> PKB -> alterations in protein and enzyme activity (INC GLUT4) -> INC glucose uptake and glycogen synthesis

Question 20

What domain binds the PO4’ed IRS-1 receptor?

Answer 20

SH2

Question 21

Where is insulin located/where does it act?

Answer 21

Muscle, adipocytes, liver

Question 22

How else can PKB promote glycogen synthesis?

Answer 22

By phosphorylating and inhibiting GSK-3

Question 23

INC phosphorylation of what contributes to insulin resistance?

What is inhibited?

Answer 23

Serine via Ser/Thr kinase instead of Tyr

IRS inhibited

Question 24

What are Ser/Thr kinases activated?

Answer 24

FFA
DAG
Ceramics
Inflammatory molecules

DIC F

Question 25

Under conditions of glucose deficiency what releases glucagon? What does this do?

Answer 25

Pancreas INC blood sugar via glycogen breakdown and inhibition of glycogen synthesis

Question 26

What also stimulates breakdown of glycogen via glucagon secretion?

Answer 26

Epinephrine

Question 27

What stimulates gluconeogensis once glycogen stores are depleted?

Answer 27

Cortisol

Question 28

What are the 3 major domains of Nuclear Receptors?

Answer 28

AF1 DBD LBD

Question 29

Which domain is highly conserved and binds to HRE?

Answer 29

DBD

Question 30

Which binding domain is independent of ligand binding and con modify the confirmation of the entire receptor?

Answer 30

AF1

Question 31

Which receptor binds to various molecules which regulates ligand-dependent activation of receptor?

Answer 31

LBD

Question 32

where is ER alpha expressed?

Answer 32

``` Female reproductive tract Mammary gland Hypothalamus Endothelial cells Vascular smooth m. ``` FEM HV

Question 33

Where is ER beta expressed?

Answer 33

``` Prostate and ovaries Lung Brain Bone Vasculature ``` BBP LV

Question 34

What is an antagonist to the ER that inactivates the transcription? What is recruited to the complex that prevents interaction with the GTA via tightening of chromatin??

Answer 34

Tamoxifen HDAC1

Question 35

What are some non-genomic ERs located?

Answer 35

In the PM in caveolae (cholesterol domains)

Question 36

What are hormone synthesized and secreted by?

Answer 36

Endocrine cells