Question 1

All genes regulated by PKA contain a cis-acting DNA sequence that binds to the phosphorylated form of a transcription factor called:

Accepted Answer

A)  β-catenin.
B)  CREB.
C)  c-Jun.
D)  TCF.E) A) and B)
F) B) and C)

Question 2

Which of the following explains why Ras is activated quickly by RTKs?

Accepted Answer

A)  RTKs phosphorylate Ras.
B)  Ras changes conformation upon ligand binding to prepare for activation.
C)  Ras binds phosphotyrosine residues on RTKs.
D)  Ras is maintained at the plasma membrane through a lipid-mediated attachment.E) None of the above
F) C) and D)

Question 3

The EGF receptor is a(n) :

Accepted Answer

A)  adapter protein.
B)  guanine nucleotide exchange protein.
C)  kinase.
D)  protease.
E)  none of the aboveF) A) and C)
G) B) and E)

Question 4

An SH2-containing protein contains a mutation that changes its binding pocket such that tyrosine and phosphotyrosine bind with equal affinity.As a result,MEK activity:

Accepted Answer

A)  decreases due to changes in Raf activation.
B)  decreases due to allosteric inhibition of SH2-domain binding.
C)  increases with ligand binding-induced dimerization.
D)  does not change with receptor dimerization and transautophosphorylation.E) All of the above
F) A) and B)

Question 5

In which of the following double-mutant flies will R7 photoreceptors develop normally?

Accepted Answer

A)  constitutively active Raf and inactive MAPK
B)  constitutively active MAPK and inactive Ras
C)  constitutively active Ras and inactive Raf
D)  all of the above
E)  none of the aboveF) A) and D)
G) C) and D)

Question 6

Before ligand binding,receptor tyrosine kinases:

Accepted Answer

A)  contain binding sites for SH2-domain containing proteins.
B)  contain activation lip tyrosines within the kinase active site.
C)  bind to GRB2 within the cytosolic domains.
D)  have excellent tyrosine kinase activity.E) A) and C)
F) C) and D)

Question 7

Which of the following is a protein kinase?

Accepted Answer

A)  EGF receptor
B)  erythropoietin receptor
C)  STAT5
D)  EGF receptor and erythropoietin receptor
E)  all of the aboveF) All of the above
G) A) and D)

Question 8

Which of the following receptors binds TGFβ?

Accepted Answer

A)  type I
B)  type II
C)  type III
D)  types I and II
E)  types II and IIIF) B) and D)
G) C) and D)

Question 9

Which of the following contain(s) an SH2 domain?

Accepted Answer

A)  SHP1
B)  SOCS
C)  STAT5
D)  all of the above
E)  none of the aboveF) A) and E)
G) A) and D)

Question 10

How does activation of protein kinase B promote cell survival?

Accepted Answer

Protein kinase B phosphorylates and inhi...

Question 11

Transcriptional activation downstream of the MAPK pathway involves:

Accepted Answer

A)  MEK.
B)  CREB phosphorylation.
C)  binding of transcription factors to the SRE of c-Fos.
D)  recruitment of Raf's N-terminal regulatory domain.
E)  Ras activation upon Sos binding.F) A) and B)
G) A) and C)

Question 12

Binding of hormone to a receptor tyrosine kinase causes all of the following,except:

Accepted Answer

A)  dimerization of the receptor.
B)  autophosphorylation of the receptor.
C)  activation of Ras through an interaction with GRB2 and Sos.
D)  hydrolysis of GTP bound to Ras.E) A) and D)
F) None of the above

Question 13

Ski and SnoN were originally identified as oncoproteins.Explain how constitutive expression of these proteins promotes cancer.

Accepted Answer

Ski and SnoN both inhibit TGFβ signaling...

Question 14

Describe the experimental approach used to determine the order of events in a signaling pathway.

Accepted Answer

The order of events in a signaling pathw...

Question 15

Which of the following signaling pathways can be activated by cytokines?

Accepted Answer

A)  JAK/STAT
B)  PI-3 kinase
C)  Ras/MAP kinase
D)  JAK/STAT and PI-3 kinase
E)  all of the aboveF) A) and D)
G) A) and C)

Question 16

TGF- β normally promotes:

Accepted Answer

A)  cell division.
B)  cell motility.
C)  tissue organization.
D)  all of the aboveE) A) and B)
F) A) and C)

Question 17

Many kinases,including MAP kinase,protein kinase B,receptor tyrosine kinases,and JAKs,possess activation lips.What is an activation lip? What modification of the activation lip is required for activation of these kinases?

Accepted Answer

The activation lip is a region...

Question 18

What feature distinguishes the ligand Delta from other ligands such as EGF,TGFα,and erythropoietin that bind transmembrane receptors?

Accepted Answer

The other ligands are diffusible molecul...

Question 19

The order of events in a signaling pathway can be determined by the analysis of mutants.Cells that express a mutant defective Raf protein cannot be stimulated to proliferate uncontrollably by constitutively active Rasᴰ (dominant active) .This indicates:

Accepted Answer

A)  quiescent cells can be induced to proliferate in the absence of growth factors if they contain a constitutively inactive mutant Raf protein.
B)  Raf is upstream of Ras in the signaling pathway.
C)  Ras is upstream of Raf in the signaling pathway.
D)  Ras mutants are recessive to Raf mutants.E) C) and D)
F) A) and D)

Question 20

How can multiple MAP kinase pathways be segregated when they share a common component?

Accepted Answer

Despite different MAP kinase pathways sh...

Exam 15: Signaling Pathways That Control Gene Activity

Binding of hormone to a receptor tyrosine kinase causes all of the following,except:

Correct AnswerverifiedShow Answer

How can multiple MAP kinase pathways be segregated when they share a common component?

Correct AnswerverifiedDespite different MAP kinase pathways sh...View AnswerShow Answer

The EGF receptor is a(n) :

Correct AnswerverifiedShow Answer

All genes regulated by PKA contain a cis-acting DNA sequence that binds to the phosphorylated form of a transcription factor called:

Correct AnswerverifiedShow Answer

Many kinases,including MAP kinase,protein kinase B,receptor tyrosine kinases,and JAKs,possess activation lips.What is an activation lip? What modification of the activation lip is required for activation of these kinases?

Correct AnswerverifiedThe activation lip is a region...View AnswerShow Answer

Which of the following receptors binds TGFβ?

Correct AnswerverifiedShow Answer

How does activation of protein kinase B promote cell survival?

Correct AnswerverifiedProtein kinase B phosphorylates and inhi...View AnswerShow Answer

TGF- β normally promotes:

Correct AnswerverifiedShow Answer

Ski and SnoN were originally identified as oncoproteins.Explain how constitutive expression of these proteins promotes cancer.

Correct AnswerverifiedSki and SnoN both inhibit TGFβ signaling...View AnswerShow Answer

Which of the following is a protein kinase?

Correct AnswerverifiedShow Answer

Which of the following explains why Ras is activated quickly by RTKs?

Correct AnswerverifiedShow Answer

Which of the following signaling pathways can be activated by cytokines?

Correct AnswerverifiedShow Answer

Before ligand binding,receptor tyrosine kinases:

Correct AnswerverifiedShow Answer

An SH2-containing protein contains a mutation that changes its binding pocket such that tyrosine and phosphotyrosine bind with equal affinity.As a result,MEK activity:

Correct AnswerverifiedShow Answer

Transcriptional activation downstream of the MAPK pathway involves:

Correct AnswerverifiedShow Answer

The order of events in a signaling pathway can be determined by the analysis of mutants.Cells that express a mutant defective Raf protein cannot be stimulated to proliferate uncontrollably by constitutively active Rasᴰ (dominant active) .This indicates:

Correct AnswerverifiedShow Answer

Describe the experimental approach used to determine the order of events in a signaling pathway.

Correct AnswerverifiedThe order of events in a signaling pathw...View AnswerShow Answer

Which of the following contain(s) an SH2 domain?

Correct AnswerverifiedShow Answer

In which of the following double-mutant flies will R7 photoreceptors develop normally?

Correct AnswerverifiedShow Answer

What feature distinguishes the ligand Delta from other ligands such as EGF,TGFα,and erythropoietin that bind transmembrane receptors?

Correct AnswerverifiedThe other ligands are diffusible molecul...View AnswerShow Answer

Correct Answer
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Correct Answer
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Despite different MAP kinase pathways sh...
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Correct Answer
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Correct Answer
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Correct Answer
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The activation lip is a region...
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Correct Answer
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Correct Answer
verified
Protein kinase B phosphorylates and inhi...
View Answer

Correct Answer
verified

Correct Answer
verified
Ski and SnoN both inhibit TGFβ signaling...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
The order of events in a signaling pathw...
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Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
The other ligands are diffusible molecul...
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