GMS 6552 CELL SIGNALING EXAM QUESTIONS AND
ANSWERS WITH COMPLETE SOLUTIONS VERIFIED
LATEST UPDATE
Problem Set 1: Mechanisms and TGFB
Which type of receptor most often utilizes second-messenger systems in its
signaling?
kinase-linked receptors
channel-linked receptors
nuclear receptors
g-protein coupled receptors
g-protein coupled receptors
- only one that utilizes second messengers
Assume you have receptor antagonists that are able to stop receptor signaling
immediately. For which type of receptor would it take the longest to see the
effects of your drug at the cellular level?
kinase-linked receptors
channel-linked receptors
nuclear receptors
g-protein coupled receptors
,nuclear receptors
- takes hours already
For which type of receptor would having adequate membrane permeability of an
agonist be most critical?
kinase-linked receptors
channel-linked receptors
nuclear receptors
g-protein coupled receptors
nuclear receptors
- the receptors are intracellularly so the agonist has to be able to get into the cell. If not
it will not work
all the others requires extracellular ligands
Is it more likely for a G-protein coupled receptor agonist to bind near the N- or C-
terminus of the receptor?
N-terminus
C-terminus
N-terminus
- the agonist is extracellular for GPCR so it will bind near the N-terminus
Is it more likely to find G-proteins bound to a GPCR that is also bound to GTP or
GDP?
GTP
GDP
,GDP
Which protein ultimately is translocated from the cytoplasm to the nucleus as a
result of JAK signaling?
JAK
GRB2
SH2
PI3K
STAT
STAT
- it will dimerize and nuclear translocation
Where, in relation to protein-coding regions of a gene, are the binding sites that
become occupied by nuclear receptors?
upstream
within the coding region
downstream
upstream
- where transcription binds
The levels of which second-messenger would be expected to increase following
administration of nitroglycerin?
Ca2+
cAMP
carbon monoxide
diacylglycerol
, cGMP
Kaboom!
cGMP
- the most common protein target for NO (nitroglycerin) is soluble guanylyl cyclase, an
enzyme that generates the second messenger cGMP.
- the signaling functions of NO begin with its binding to protein receptors on or in the
cell. The binding sites can be either: a metal ion in the protein or one of its S atoms
(e.g., on cysteine).
does TGF-B treatment cause cells to grow more or less in soft-agar assay?
more
less
more
- in the absence of TGF-B, cells will actually die
the latent TBF-B peptide must be cleaved by what protease in order to be
activated?
plasmin
trypsin
papain
chymotrypsin
PARP
plasmin
in the TGF-B pathway, which protein becomes activated first upon binding of a
ligand?
ANSWERS WITH COMPLETE SOLUTIONS VERIFIED
LATEST UPDATE
Problem Set 1: Mechanisms and TGFB
Which type of receptor most often utilizes second-messenger systems in its
signaling?
kinase-linked receptors
channel-linked receptors
nuclear receptors
g-protein coupled receptors
g-protein coupled receptors
- only one that utilizes second messengers
Assume you have receptor antagonists that are able to stop receptor signaling
immediately. For which type of receptor would it take the longest to see the
effects of your drug at the cellular level?
kinase-linked receptors
channel-linked receptors
nuclear receptors
g-protein coupled receptors
,nuclear receptors
- takes hours already
For which type of receptor would having adequate membrane permeability of an
agonist be most critical?
kinase-linked receptors
channel-linked receptors
nuclear receptors
g-protein coupled receptors
nuclear receptors
- the receptors are intracellularly so the agonist has to be able to get into the cell. If not
it will not work
all the others requires extracellular ligands
Is it more likely for a G-protein coupled receptor agonist to bind near the N- or C-
terminus of the receptor?
N-terminus
C-terminus
N-terminus
- the agonist is extracellular for GPCR so it will bind near the N-terminus
Is it more likely to find G-proteins bound to a GPCR that is also bound to GTP or
GDP?
GTP
GDP
,GDP
Which protein ultimately is translocated from the cytoplasm to the nucleus as a
result of JAK signaling?
JAK
GRB2
SH2
PI3K
STAT
STAT
- it will dimerize and nuclear translocation
Where, in relation to protein-coding regions of a gene, are the binding sites that
become occupied by nuclear receptors?
upstream
within the coding region
downstream
upstream
- where transcription binds
The levels of which second-messenger would be expected to increase following
administration of nitroglycerin?
Ca2+
cAMP
carbon monoxide
diacylglycerol
, cGMP
Kaboom!
cGMP
- the most common protein target for NO (nitroglycerin) is soluble guanylyl cyclase, an
enzyme that generates the second messenger cGMP.
- the signaling functions of NO begin with its binding to protein receptors on or in the
cell. The binding sites can be either: a metal ion in the protein or one of its S atoms
(e.g., on cysteine).
does TGF-B treatment cause cells to grow more or less in soft-agar assay?
more
less
more
- in the absence of TGF-B, cells will actually die
the latent TBF-B peptide must be cleaved by what protease in order to be
activated?
plasmin
trypsin
papain
chymotrypsin
PARP
plasmin
in the TGF-B pathway, which protein becomes activated first upon binding of a
ligand?
