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MECHANISMS OF SIGNAL TRANSDUCTION, October 2009.
COURSE TEST.
Please submit your test before November 21 by e-mail ([email protected]) or
mail (Farmakologisk institutt, Pb 1057 Blindern, 0316 Oslo). You will not receive your
course certificate until the test has been submitted.
Please answer the questions briefly. You may answer in Norwegian or English.
1) Describe the main types of membrane receptors.
2) Describe how cholera toxin and pertussis toxin affect adenylyl cyclase activity and
cAMP accumulation.
3) How do steroid hormones exert their effects?
4) How are heterotrimeric and monomeric (small) G proteins, respectively, activated and
deactivated? How can extracellular signaling affect these processes?
5) How is signaling specificity from receptor tyrosine kinases determined?
6) Which are the principal enzymes that use phosphatidylinositol 4,5-bisphosphate (PIP2)
as substrate, and what are the main functions of the products of these reactions?
7) Describe the typical time course of intracellular calcium elevation following activation
of a G protein-coupled receptor and explain how the different phases are generated.
8) What are the main components of the cell cycle machinery, and how are these
regulated by extracellular signaling?
9) Give some examples of different ion channels and describe how they are regulated by
extracellular signals.
10) Describe the principal mechanisms for regulation of gene transcription by
extracellular signaling.
11) How are transcription factors in the cytosol transported into the nucleus?
12) How are phospholipases regulated by receptor stimulation?
13) What is protein kinase C, and how is it regulated?
14) How is the cellular level of cAMP regulated?
15) What are the main targets of cAMP?
16) What are the main targets of DAG?
17) How is NO generated, and how does it exert its effects?
18) What are the main functions of
-Ras
-Rho
-Ran
19) What is calcineurin, and how is it regulated?
20) What is desensitization, and what are the main mechanisms involved in this process?
21) Which of the following effector enzymes are believed to be regulated by βγ-subunits
of heterotrimeric G proteins?
-PI-PLC
-PLA2
-Adenylyl cyclase
-Guanylyl cyclase
-Protein kinase C
22) Describe how the intracellular tyrosine kinase Src is activated and deactivated.
23) What is the role of SH2 and SH3 domains that have been identified in many proteins?
24) How does internalization of receptors affect signaling?
25) What do we understand by the term receptor transactivation, and how does it occur?