Biochem - Genes

Question 1

What is the p53 gene?

Answer 1

A tumour suppressing gene

Mutated in 60% of all cancers

Question 2

How does the p53 gene work?

Answer 2

Causes anti growth (apoptosis, cell cycle arrest, autophagy) in cells in response to stimuli which could cause cancer e.g hypoxia, DNA mutation

Question 3

The genes for which TFs are inserted into mouse mesenchymal cells to make them produce insulin?

Answer 3

MafA, NeuroD1, PDX-1

Question 4

What does lacA produce?

Answer 4

Beta galactoside transacetylase - acetylates lactose

Question 5

What does lacZ produce

Answer 5

Beta galactosidase - cleaves lactose into glucose and lactose

Question 6

What does lacY produce?

Answer 6

Lactose permease - transports lactose into the cell

Question 7

Mef2

Answer 7

Myocyte enhancer factor2. (A TF)
Turns on many muscle specific genes when activated including genes for myoglobin, myosin heavy chain, slow Troponin I

Question 8

What control mef2 activity?

Answer 8

HDAC4 and HDAC 5

Question 9

What is NFAT

Answer 9

Turns on muscle specific genes

Question 10

How is nfat activated

Answer 10

Ca++ binds calmodulin , this complex activates calcineurin
Calcuneurin dephosphorylates nfat
Nfat translocates into nucleus and turns on muscle specific genes

Question 11

What is MuRF-1

Answer 11

A ubiquitin ligase

Question 12

What is atrogin-1?

Answer 12

A ubiquitin ligase

Question 13

What is myogenin

Answer 13

A transcription factor which up regulates the expression of MuRF1 and atrogin 1

Question 14

Mutations in what genes cause HNPCC?

Answer 14

Genes for mismatch repair pathway (MMR)

MLH1
MSH2
MSH3
MSH6
PMS1
PMS2