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TLS Online TPP Program

#Question id: 15364

In normal cells, FOS and MYC mRNAs and the proteins they encode are intrinsically unstable and degrade rapidly after the genes are transcribed, Conversion of the MYC proto-oncogene into an oncogene can occur by different mechanisms, Other members of this protein set include MAD, MAX, and MNT, choose incorrect statement regarding this,

#Unit 4. Cell Communication and Cell Signaling
  1. MYC-MAX dimers regulate genes that control proliferation, such as cyclins. 
  2. MAD and MNT work with the SIN3 co-repressor protein to bring in histone deacetylases that help to block transcription.
  3. MAD proteins inhibit MYC proteins, which has led to an interest in using MAD proteins, or drugs that stimulate MAD proteins, to rein in excessive MYC activity that contributes to tumor formation.
  4. MYC protein complexes affect transcription by recruiting chromatin-modifying complexes containing histone deacetyl transferases.
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TLS Online TPP Program

#Question id: 1230

#Unit 4. Cell Communication and Cell Signaling

Which of the following events occur(s) following the binding of a ligand to a G protein–coupled receptor that triggers release of Ca2+?

a. activation of protein kinase A by IP3

b. phospholipase cleavage of PIP2 to IP3 and DAG

c. release of DAG into the cytosol

d. IP3-mediated opening of Ca2+ channels in the ER membrane
TLS Online TPP Program

#Question id: 1231

#Unit 4. Cell Communication and Cell Signaling

Arrange the following events in the proper order in which they occur during transduction of the TGFβ signal:

a. association of Smad3 and Smad4  

b. phosphorylation of TGFβ receptor I by TGFβ receptor II            

c. phosphorylation of Smad3 by TGFβ receptor I     

d. nuclear import of Smad3   

e. binding of TGFβ to TGFβ receptor II  
TLS Online TPP Program

#Question id: 1232

#Unit 4. Cell Communication and Cell Signaling

Which of the following mutations might confer a competitive advantage to an athlete by raising his or her hematocrit?

a. excess production of erythropoietin                       

b. decreased production of erythropoietin

c. EpoR that cannot bind STAT5                  

d. EpoR that cannot bind SHP1

e. EpoR that cannot bind JAK2
TLS Online TPP Program

#Question id: 1233

#Unit 4. Cell Communication and Cell Signaling

Transphosphorylation (cross-phosphorylation) of receptor tyrosine kinases

a. inhibits catalytic activity.

b. promotes transphosphorylation of additional tyrosine residues.

c. triggers release of the ligand.

d. generates binding sites for signaling molecules.
TLS Online TPP Program

#Question id: 1234

#Unit 4. Cell Communication and Cell Signaling

Which of the following mutations would likely have a similar cancer-promoting effect as the RasD mutation?

a. mutation in Grb2 so that it cannot bind Sos

b. mutation in Sos so that it binds Ras independent of Grb2

c. mutation in GAP so that it cannot bind Ras

d. mutation in EGF receptor so that it binds GRB2 independent of EGF
TLS Online TPP Program

#Question id: 1235

#Unit 4. Cell Communication and Cell Signaling

Arrange the following events in the proper order in which they occur during transduction of the EGF signal:

a. transphosphorylation of the EGF receptor

b. dissociation of GDP from Ras                   

c. dissociation of Ras from Sos         

d. binding of GRB2 to the EGF receptor      

e. binding of GTP to Ras