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PHTX 537 EXAMINATION 1 2002
DATE: Thursday, September 12th
FROM: Edward JN Ishac, Course Director
NOTE: This exam is scheduled to last for 2 HOURS. Apportion your time to
approximate 1 minute per point value.
Please write the last 4 digits of your social security number on each page of the
exam.
Also please answer the questions from each lecturer on separate pages from
those of the others.
Finally, before answering the following questions, read and analyze them carefully
to identify the information being requested. When you have done this, write your
response, using the same organizational format as the question. Be sure to
address each point raised in the question, but you are strongly discouraged from
including extraneous information not asked for (even though you may be very
eager to demonstrate your knowledge).
There are FIVE exams scheduled for this course. The questions will be as they
were in the past, i.e. multiple choice questions, short answer and/or essay type
questions. Each exam will be worth 100 points, so figure on an 8-10 point
question that should take 8-10 minutes to answer per lecture hour. There is no
cumulative final exam, so all exams are weighted evenly in the final grade.
GOOD LUCK
PHTX 537
Receptor: Cell Signaling
Fall Semester 2002
Dr. Selley
Examination 1
55 points total
Section 1: Short answer (12 points total, 2 pts each)
1. What is the rate-limiting step in G-protein activation?
2. Second messenger-activated kinases phosphorylate which two amino acid
residues on proteins?
3. What family of G is most associated with stimulation of phospholipase C?
4. Phospholipase D (PLD) generates which second messenger in large amounts?
5. Soluble guanylyl cyclases are most strongly activated by what?
6. The G-gamma-like (GGL) domain of many large regulators of G-protein
signaling (RGS) proteins, allows the RGS to heterodimerize with what?
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Receptor: Cell Signaling
Dr. Selley
continued
Section 2: Short answer (15 points total, 3 pts each)
7. What are two ways that regulators of G-protein signaling (RGS) proteins can
attenuate G-protein signaling?
8. Ca++/calmodulin kinase (CaMK) type IV is maximally activated when which two
conditions are present?
9. The major isoforms of protein kinase C (PKC) are activated by which two
second messengers?
10. What are two ways by which adenylyl cyclase type I can be inhibited?
11. What are two factors that can stimulate epithelial nitric oxide synthase
(eNOS)?
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Receptor: Cell Signaling
Dr. Selley
continued
Section 3: Upstream/downstream. For each of the following signaling
components, please identify (12 points total, 3 pts each):
a) what it does
b) the immediate upstream activator
c) a downstream target
12. cGMP-phosphodiesterase
a.
b.
c.
13. Protein kinase A (PKA)
a.
b.
c.
14. NMDA receptor
a.
b.
c.
15. Inositol triphosphate (IP3) receptor
a.
b.
c.
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Receptor: Cell Signaling
Dr. Selley
continued
Section 4: Short essay (16 points total)
16. Describe the basic structure, function and mechanism of action of the
cytoplasmic steroid type receptors? (7 points)
17. Describe start to finish the process of homologous desensitization and
downregulation of a GPCR by G-protein-coupled receptor kinase 2 (GRK2) (9
points).
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Receptor Theory
Dr. Martin
45 points total
Question 1. (20 points)
Please compare the theories of Clark, Stevenson and Paton as follows:
A. State the basic premise of each theory
B. What is the contribution of each theory
C. Describe limitations of each theory
D. Define agonist, partial, and antagonist according to each theory
Question 2. (15 points).
Please provide a brief description of how receptor affinity and receptor number
are determined using binding assays. What are the criteria that are use to
distinguish receptors from non-receptor binding sites.
Question 3. (10 points)
Discuss the ternary model that best describes the equilibrium between a ligand,
receptor and G-protein at both resting and activated states.
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