2

Question 1

Galphas

Answer 1

activate adenylate cyclase, raise substrate AMP

Question 2

GalphaIs

Answer 2

inhibit adenylate cyclase, lower substrate AMP

Question 3

Phospholipase A2 can activate

Answer 3

arachidonic acid.

Question 4

Major thing activated by GalphaIs

Answer 4

Phospholipase A2.

Question 5

——- is the source of prostaglandins

Answer 5

arachidonic acid

Question 6

Prostaglandins are

Answer 6

used in pain and inflammation signaling

Question 7

IP3 binds

Answer 7

ER to release calcium

Question 8

PIP2

Answer 8

leads to changes in gene expression (transcription factors). Breakdown of Gqs by PLC beta (other product is IP3)

Question 9

PIP2 serves as substrate for

Answer 9

phospholipase C

Question 10

Phosphatidyl

Answer 10

ids something as a phospholipid

Question 11

DAG activates

Answer 11

protein kinase C

Question 12

*Most isoforms of PKC regulated by

Answer 12

DAG (DAG allows the enzyme to bind Ca++ tighter. Therefore, the enzyme can function at lower Ca++ concentrations

Question 13

the trimeric G protein gets turned on, but

Answer 13

turns itself off.

Question 14

Meanwhile, the agonist-GPCR complex is free to

Answer 14

activate other trimeric G proteins with which it comes in contact.

Question 15

Desensitization of GPCRs by

Answer 15

endocytosis - chronic usage

Question 16

Endocytosed receptors can either be

Answer 16

recycled or degraded

Question 17

Ligands

Answer 17

: Growth factors, differentiation factors, cytokines

Question 18

Receptor tyrosine kinase:

Answer 18

Receptors either contain an intrinsic tyrosine kinase enzyme or an extrinsic tyrosine kinase enzyme

Binding of ligand leads to dimerization of the receptor

Some receptors form homodimers, some receptors form heterodimers, and some receptors do both.

Dimerization leads to transphosphorylation of receptors

Tyrosine phosphorylation of receptors leads to docking of signaling molecules

The positioning of proteins near the membrane leads to different cascades of signaling

Question 19

Receptor tyrosine kinase:

Receptors either contain an

Answer 19

intrinsic tyrosine kinase enzyme or an extrinsic tyrosine kinase enzyme

Question 20

Receptor tyrosine kinase:

Binding of ligand leads to

Answer 20

dimerization of the receptor

Question 21

Receptor tyrosine kinase:

Some receptors form ——-, some receptors form ———-.

Answer 21

homodimers

heterodimers, and some receptors do both

Question 22

Receptor tyrosine kinase:

Dimerization leads to

Answer 22

transphosphorylation of receptors

Question 23

Receptor tyrosine kinase:

Tyrosine phosphorylation of receptors leads to

Answer 23

docking of signaling molecules

Question 24

Receptor tyrosine kinase:

The positioning of proteins near the membrane leads to

Answer 24

different cascades of signaling

Question 25

JAK-STAT signaling mediates….

Answer 25

mediates immune proccesses, development.

Used for a quick change in gene expression

Question 26

JAK-STAT;

Answer 26

1. Binding of ligand (cytokine) leads to phosphorylation of receptor by JAK kinase
2. This leads to binding of STAT protein (one of six) to the phosphorylated receptor
3. These leads to phosphorylation of STAT protein by Jak kinase
4. This leads to dimerization of STAT protein
5. This leads to translocation of STAT dimer to nucleus and transcriptional activation of panels of genes

Question 27

STAT monomers contain both an SH2 domain and a tyrosine that can be

Answer 27

phosphorylated

Question 28

Nuclear Hormone Receptors

Answer 28

Steroid hormone receptors - inside cell somewhere.

Question 29

Class 1 nuclear receptors

*Exist as a complex with ———– in the absence of ligand.

Answer 29

heat shock proteins in the absence of ligand

Question 30

Class 1 nuclear receptors

*Ligand binding induces the complex to

Answer 30

fall apart, form a homodimer, and bind to its specific DNA response element

Question 31

Class 1 nuclear receptors

*Once bound to its specific response element it binds —————– to stimulate transcription

Answer 31

coactivators

Question 32

Class 2 nuclear receptors

*Binds to target DNA at its specific response element in the

Answer 32

absence of ligand

Question 33

Class 2 nuclear receptors

*Binds ——— in the absence of ligand and repressses transcription

Answer 33

corepressors
*Form homo and heterodimers

take acetyl group off lysine, making histone more positively charged and strenthening interactions between DNA and protein.

Question 34

Class 2 nuclear receptors

*Ligand binding produces a switch from binding ——-to binding—————

Answer 34

corepressors

coactivators

Question 35

Class 1 nuclear receptors cause histones to be

Answer 35

less positively charged, weakening the interaction with chromatin.