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Created by Abigail Leslie
about 2 years ago
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Transcription Regulation
Housekeeping genes
Unique or differentiation specific genes
Chromatin
Chromosomes
Euchromatin
Heterochromatin
First DNA packing stage
Histones
Nucelosome
H2A - H2B - H3 - H4
H3-H4 Heterotetramer
H2A-H2B Dimer
H1
Beads on a string
Histone Core
Histone Tail
30 nm fiber
False
True (Nucleosome formation is preferential at certain DNA sequences)
Nuclesome Formation
Heterochromatin
Histone Acetylation
HATs (Histone Acetyltransferases)
HDACs (Histone Deacetylases)
Methylation of H3 Lysine 9
Methylation of H3 Lysine 4
Histone Methylation
Chromodomains
Histone code
Histone Phosphorylation
Histone Ubiquitination
Chromatin Remodeling Complexes
• ATPase domain (universal)
• Bromodomain (binds acetylated lysines)
• Chromodomain (binds methylated lysines)
• SANT-SLIDE (binds histone tails)
One Model: CRC creates a distortion around the histone octamer, which results in sliding of octamer to a new position on the DNA
Direct DNA modification
DNA methyltransferase
Methylated cytosines are more likely to undergo spontaneous deamination
5-M cytosine will deaminate into Tyrosine
DNA methylation
X-chromosome inactivation
In females, one X chromosomes is deactivated. An effect of this occurs in cats, where coloring is connected to the X chromosome. Depending on the X gene deactivated, causes different patches of colored fur.
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