Chromatin and Epigenetics Flashcards
Complex of DNA and proteins found in eukaryotes
Chromatin
Inheritable changes in chromatin that cause phenotypes and can be passed from cell to cell and from generation to generation
Epigenetics
A mechanism for affecting transcription that changes the distribution or composition of histones. Repositioning nucleosomes, removing nucleosomes, and replacing histones with variant forms usually activates transcription
Chromatin Remodelers
A mechanism for affecting transcription that adds or removes chemical groups to histones
Histone Modifiers
The mechanism for affecting transcription that is the methylation of cytosine bases, usually represses transctiption
DNA methylation
An ATP dependent, multi-subunit complex that can open chromatin structure by repositioning or ejecting nucleosomes. It weakens interaction of DNA in nucleosomes and facilitates movement of histone octamers
SWI/SNF
Which tails of histones can be modified through methylation, acetylation, phosphorylation, and ubiquitination
N-terminal tails
What three things influence the type of epigenetic histone modification
Histone Protein, Amino acid position, type of modification
A histone modification that can activate or repress transcription
Methylation
The proteins that add methyl groups to histones
Histone methyltransferases (HMTs)
The proteins that remove methyl groups from histones
Histone demethylases (HDMTs)
A histone modification that usually activates transcription
Acetylation
The proteins that add acetyl groups to histones
Histone acetyl transferases (HATs)
The proteins that remove acetyl groups from histones
Histone deacetylases (HDACs)
A method for assessing chromatin structure, open chromatin is more sensitive to digestion by DNase, these sites often occur near promoters, enhancers, and other regulatory sequences
DNase hypersensitivity
