Epigenetics, Gene Regulation and Disease - Histone Modifications

Flashcards covering key vocabulary and concepts related to histone modifications, gene regulation, and epigenetics.

DNA Methylation

Addition of methyl groups to the cystine residues of DNA

Histone Modifications

Histone tail modifications to alter properties of DNA

Nucleosome positioning

Positioning of nucleosomes around the transcription start sites

Activators

Proteins that bind to genes at enhancers and speed up transcription

Repressors

Proteins that bind to genes at silencers and slow down transcription

Heterochromatin

Tightly packed chromatin associated with repressed transcription.

Euchromatin

Lightly packed chromatin associated with active transcription.

Writers/Initiators/Establishers

De novo methylation

Maintainers

Dnmt1

Readers

DNA methylation binding proteins, transcription factors

Erasers

Deacetylases, demethylases, phosphatases

Histone acetyltransferase enzymes (HAT/KAT)

Enzymes that carry out histone acetylation.

Histone de-acetyltransferases (HDAC/KDAC)

Enzymes that carry out the de-acetylation of histones

Methylation Reaction

Process of substituting an active hydrogen atom of a protein for a methyl- group (CH3)

Histone methyl-transferase enzymes (HMT)

Enzymes that carry out histone methylation

Histone de-methylases (HDM)

Enzymes that carry out the de-methylation of histones

Repressive histone mark

H3K27me3

Active Histone Mark

H3K4me3

Histone modifications

Histone ADP-ribosylation

Histone modifications

Histone citrullination

Ubiquitination reaction

The process of substituting an active hydrogen atom of a protein for one or more ubiquitin groups

Histone ubiquitination

Ubiquitin molecules to the hydroxyl group of lysine residues present in N-terminal tails

Histone modifications

Histone ADP-ribosylation

SUMOylation

involves the covalent attachment of small ubiquitin-like modifier molecules