L9 Epigenetics Flashcards
Epigenetic regulation
- determines cell fate
- causes heritable differences in level of expression of a gene without changes in DNA sequence
Euchromatin
open, active transcription
constitutive heterochromatin
condensed, transcriptionally inactive e.g. centromeres
facultative heterochromatin
dynamic changes of transcriptional state (developmentally controlled)
Epigenator
e.g. differentiation signals, temperature variation
Epigenetic initiator
e.g. DNA binding factors, ncRNA
Epigenetic maintainer
e.g. histone/DNA modifiers, histone variants
Histone code
combination of modifications determines transcriptional outcome
SAM
S-adenosyl-methionine-transferases
ChIP
Chromatin immunoprecipitation
Immunodominance
Immunodominance is the immunological phenomenon in which immune responses are mounted against only a few of the antigenic peptides out of the many produced.
Chromodomain
A chromodomain (chromatin organization modifier) is a protein structural domain of about 40–50 amino acid residues commonly found in proteins associated with the remodeling and manipulation of chromatin.
Chromoshadow domain
dimerises to compact chromatin
Cofactors
Coenzymes
Cofactors, mostly metal ions or coenzymes, are inorganic and organic chemicals that assist enzymes during the catalysis of reactions.
Coenzymes are non-protein organic molecules that are mostly derivatives of vitamins soluble in water by phosphorylation; they bind apoenzyme to proteins to produce an active holoenzyme.
Histone variants
Histone variants are proteins that substitute for the core canonical histones (H3, H4, H2A, H2B) in nucleosomes in eukaryotes and often confer specific structural and functional features.
