Histone Modifications and Variants Flashcards
(40 cards)
1
Q
H4K5 Ac
A
Tx active
2
Q
H4K8 Ac
A
Tx active
3
Q
H4K12 Ac
A
Tx active
4
Q
H4K16 Ac
A
Tx active
5
Q
H3K9 Ac
A
Tx active
6
Q
H3K14 Ac
A
Tx active
7
Q
H3K27 Ac
A
Tx active
- enhancer
8
Q
H3K4 Me
A
Tx active
- Methylated by MLL/SET1
- Me1 –> active enhancer
- Me3 –> active promotor (CpG) –>recruited by TFIID
- Me2 –> downstream in gene –> Set3 HDAC –> Less H3/H4 acetylation in 5’ end of genes
- H3K4me3 inhibits Dnmt3 –> reinforces the DNA hypomethylated state
9
Q
H3K36 Me
A
Tx active
H3K36me3:
- All regions of the gene, mostly to the end
- methylated by SET2 (attracted by CTD-Ser2-Ph)
- and then recruits HDAC complexes
-H3K36 promotes Dnmt3
10
Q
H3K79 Me
A
Tx active
- Located primarily near start of gene, gradient to end of gene
11
Q
H3S10 Ph
A
Tx active (also involved in mitosis/chromosome segregation)
12
Q
H2BK120 Ub1
A
Tx active
Required for:
- H3K4 me2/me3 (SET1/compass)
- H3K79me3 (Dot1L)
Removed by DUB-domain of STAGA
13
Q
..R. Me
A
Tx active (methylated H4R3 facilitates H4 acetylation)
14
Q
H4 deAc
A
Tx inactive
15
Q
H3K. deAc
A
Tx inactive
16
Q
H3K9 Me3
H3K9me2
A
H3K9me3:
Tx inactive
- Methylated by SUV3-9
- constitutive heterochromatin
H3K9me2 (Trx inactive mark, around TSS):
- prohibiting acetylation
- recruiting transcriptional repressors
- Bound by Stella in the maternal pronucleus and protects 5mC from TET3-mediated conversion into 5hmC
17
Q
H4K20 Me
A
Tx inactive
18
Q
H3K27 Me
A
Tx inactive
- Methylated by EZH2
- Polycomb regulated genes
- H3K27 at repressed promotors
19
Q
H3K4 deMe
A
Tx inactive
- Me3 –> active promotor
- Me1 –> enhancer
20
Q
H1K26 Me
A
Tx inactive
- Methylated by Ezh2
21
Q
H2AK119 Ub1
A
Tx inactive (PcG mediated silencing) - At repressed promotor
22
Q
H2A.Z
A
- Promotes transcription
- 5” end of genes (beginning of gene)
- Heterochromatin boundaries
- Incorporated by Swr1, removed by Ino80
- Less stable than H2A
23
Q
macroH2A
A
- Mainly on inactivated X-chromosome
- Reduces recruitment of SWI/SNF crc
24
Q
H2A.Bbd
A
- Active regions
- Loose chromatin
- Spermatogenesis
25
H3.3
- Nearly identical to H3 (A31S)
- H3.3S31 Ph --> chromotin compaction
- Transcribed regions, promotors, enhancers
- If nucleosome is lost independent of replication, a H3.3/H4 dimer is placed as repair
- Inhibits H1
26
H1
- Everywhere, eu- & heterochromatin
- Lower H1 near TrStSi and active genes
- Low H1 --> High H3.3!
- H3.3 inhibits H1
- H1 --| HMT (histon methyl transferase)
- H1 --> DNA methyltransferase --> DNA methylation
27
H2B.FWT
- Enriched at telomeres
| - Expressed in testes only
28
H2A.X
- DNA repair (NHEJ)
29
CENP-A
- H3 variant in centromere
| - Determines the kinetochore position(s) on each chromosome
30
EZH2
Methylates:
- H3K27 Me3
- H1K26 Me
31
MLL/Set1
Methylates:
- H3K4 Me
Recruited to 5' end of genes by CTD-Ser5-Ph
32
SUV39
Methylates:
| - H3K9 Me
33
Bromo domain recognizes:
Acetylation
34
Chromo domain recognizes:
K-Me (methylated lysines)
35
PHD domain recognizes:
K-Me (methylated lysines)
36
Tudor domain recognizes:
K-Me (methylated lysines) and R-Me (methylated arginines)
37
H4K8
in enhancer, recruits Swi/Snf
38
H3K4me0 + H3K36me3
Signal for de novo methylation
39
PolyUb protein with K48Ub
leads to degradation by the ubiquitin-dependent proteasome
40
PolyUb protein with K63Ub
Signal specific pathway
