Signaling

Question 1

What is a transcription factor?

Answer 1

A protein that increases transcription that is very specific for the gene that it activates

Question 2

What are the three parts of a signaling cascade?

Answer 2

Reception
Transduction
Response

Question 3

What are 3 domains of a transcription factor?

Answer 3

Dimerization domains
Trans acting domains
DNA binding

Question 4

What are the two driving forces in development?

Answer 4

Cell fate determination - differentiation of cells during embryology
Morphogenesis - cell types organizing into specific tissues, organs…

Question 5

What is a teratogen?

Answer 5

Anything that causes a structural abnormality after fetal exposure during pregnancy

Question 6

Protooncogenes

Answer 6

Positive regulators of cell growth

Question 7

Tumor suppressor genes

Answer 7

Negative regulators of cell growth

Question 8

Describe the basic signaling of a GPCR

Answer 8

Ligand binds, GDP bound to the alpha subunit turns into GTP and dissociates from the beta and gamma subunits. The complex then interacts with enzymes creating second messengers, then the alpha subu hydrolyzes the GTP to GDP and heads back to recombine with the beta and gamma and the cycle starts over again

Question 9

Types of receptor ligands

Answer 9

Agonist - bind and activate

Antagonist binds and represses

Question 10

4 second messengers we care about

Answer 10

cAMP, IP3, DAG, Ca2++

Question 11

Reaction creating cAMP

Answer 11

Hydrolysis of ATP to cAMP using adenylate cyclase

Question 12

Reaction creating IP3 and DAG

Answer 12

PIP2 cleavage into IP3 and DAG from phospholipase C

Question 13

Reaction creating Ca2++

Answer 13

IP3 activates the IP3 gated calcium channel and allows calcium to flow into the cell and act as a second messenger

Question 14

What do protein kinases do?

Answer 14

Transfer phosphate groups to ser, thr, or tyr

Question 15

True or false. RTKs act as a receptor and enzyme.

Answer 15

True.

Question 16

Describe the pathway of RTKs

Answer 16

Ligand binds, RTKs dimerize and the now active kinase will phosphorylate tyr residues which will activate downstream relay proteins

Question 17

Example of RTK

Answer 17

Insulin receptor and growth factors (anti cancer agents as tyr kinase inhibitors)

Question 18

What are cytokine receptors involved in?

Answer 18

Immune system signaling molecules (interferons and interleukins)

Question 19

Describe pathway of cytokine receptor

Answer 19

Bind cytokine and transduce signal

Question 20

What type of molecules bind to intracellular/nuclear receptors?

Answer 20

Steroids or lipids