Histone deacteylase inhibtors and Hypomethylating agents

Question 1

What is epigenetics

Answer 1

study of phenotypic changes that do not involve changes in the DNA sequence

Question 2

T/F: Heterochromatin are the parts of the chromatin that is expressed while Euchormatin is not

Answer 2

False: Euchromatin are the parts of the chromatin that are expressed while heterochromatin are not

Question 3

What are the three main ways that chromatin can be modified

Answer 3

Methylated, acetylated, and phosphorylated

Question 4

What are the writers of histones, erasers

Answer 4

Acetylators, methylators, kinases/ Deacetylators, demethylators, and phosphatases

Question 5

What is the effect that acetylators have on histones

Answer 5

Acetlylation removes the positive charge of the histone making the chromatin more relaxed and easier to access

Question 6

What are the chromatin readers and what do they recognize

Answer 6

MBD recognize methylated DNA, Bromodomain recognize acetylated histones, chromodomain AND phd AND wd40 recognize methylated histones

Question 7

T/F: TET remove DNA methyl marks, KDM and RDM are histonedemethylases that remove methyl marks

Answer 7

True

Question 8

What parts of the DNA is methylated

Answer 8

Cytosine bases of Eukaryotic DNA converted to 5-methylatedcytosine

Question 9

What motif does methylation of DNA almost always occur at

Answer 9

CPG

Question 10

T/F: Promoters of actively transcribed genes are unmethylated while promoters of transcriptionally silecned genes are methylated

Answer 10

True

Question 11

What proteins methylate DNA and what are they/ source of the methyl group

Answer 11

DNMT1, DNMT2, DNMT3/ SAM

Question 12

What is the mechanism of demethylation

Answer 12

methyl groups are hydroxylated

Question 13

How DNA hypomethylation (active genes) characterized by which promoters

Answer 13

H3K4me3, H3, and H4 acetylation

Question 14

What is the only approved DNMT inhibitor/ how

Answer 14

5-aza-c (azacitidine, Vidaza)/ Converted to trinucleotides and incorporated into DNA/RNA respectively OR covalently modifies DNMT

Question 15

What are the 4 most known ways histones are changed

Answer 15

Lysine acetylation, Lysine and arginine methylation, serine/threonine/tyrosine phosphorylation, serine/threonine ubiquitination

Question 16

T/F: HAT adds acteyl group while HDAC removes acetyl groups

Answer 16

True

Question 17

What are the two most know deacetylase complexes, what are they dependent on

Answer 17

HDACs and SIRTS/ HDACs: Zinc, SIRTuins: are nicatinamide adenine di-nucleotide (NAD) dependent

Question 18

What class of HDACs are responsible for deactylation of histones

Answer 18

Class 1

Question 19

What are the HDAC inhibitors

Answer 19

Valproic acid, Vorinistat, Romidespin, Belinostat, Panobinostat

Question 20

Why is zinc important in deactylation, how do HDAC inhibitors

Answer 20

Primes the acetyl group for hydrolysis, Inhibitor forms bidentate chelate with Zinc