Lecture 5 + 6

Question 1

Is c-myc is translocated in Burkitt’s Lymphoma

Answer 1

yes

Question 2

How are MYC gene placed under highly active
transcriptional regulators

Answer 2

Translocation of c-myc to Ig Heavy chain locus

Question 3

Is c-myc translocation sufficient for malignancy

Answer 3

No

Question 4

How does MYC-MAX generate gene transcription

Answer 4

MYC-MAX heterodimer binds to E-box sequence CACGTG of target genes (or with noncanonical sequences) to regulate gene transcription

Question 5

What targets MYC for degradation-mutations

Answer 5

Phosphorylation at Thr58

Question 6

How is MYC stabilised

Answer 6

MYC is stabilised with phosphorylation at Ser62 by MAPK, a Ras downstream effector.

Question 7

What do the TSGs p16 and ARF target

Answer 7

• target p53
  Oncogenic stress-oncoprotein MYC-leads to E2Fs increase expression of ARF-activates p53 by binding to and sequestering its negative regulator MDM2. p53 levels
  increase in the cell-leads to G1 and G2 arrest.

Question 8

Is overexpression of MYC alone suffice to lead to cancer?

Answer 8

No, MYC alone cannot cause mitotic cellular division. Moreover, MYC overexpression can enforce replication in a manner that results in DNA breaks. This appears to be the consequence of several mechanisms. MYC may directly block double-stranded DNA repair and/or increase oxidative damage, causing DNA damage.

Question 9

How does MYC activate Telomerase

Answer 9

by inducing expression of its catalytic subunit, telomerase reverse transcriptase
(TERT).

Question 10

Does MYC binds MAX, to become transcriptionally active

Answer 10

Yes

Question 11

How can MYC alter its transcriptional ability as well as its interaction with various interacting proteins

Answer 11

It is modified through various post-translational events including phosphorylation, acetylation and ubiquitination

Question 12

What transcription factor is MYC

Answer 12

MYC is a bHLH leucine zipper transcription factor

Question 13

What is involved in the positive regulation of MYC protein stabilization

Answer 13

MAPKs

Question 14

MYC/MAX leads to the increased expression of target genes which have an E-Box of what genes

Answer 14

These include CDK4, CCND2 (gene for CyclinD2), CUL1.

Question 15

MYC can become deregulated through chromosomal translocations as seen in Burkitt’s lymphoma

Answer 15

Yes

Question 16

Does MYC Leads to increased expression of VEGF contributing to angiogenesis

Answer 16

Yes

Question 17

To promote passage through the G1 division checkpoint R, the c-Myc protein must be fully activated by which process or processes

Answer 17

Dimerization with the Max protein, and phosphorylation at the Transactivation domain (TAD)

Question 18

The active C-MYC protein binds to the EBox (enhancer box) of DNA to

Answer 18

Enhance transcription of the gene encoding CDK4