Control of Gene Expression in Eukaryotes

These flashcards cover key terms and concepts related to the control of gene expression in eukaryotes, focusing on mechanisms of transcriptional regulation.

Transcriptional activation

A process that promotes the initiation of gene transcription by recruitments or interactions with key transcription machinery.

Transcriptional repression

Mechanisms that inhibit the transcription of genes, often involving chromatin modifications or repression proteins.

Chromatin modification

Chemical alterations to chromatin that influence gene expression by impacting accessibility of DNA to transcription machinery.

Heterochromatin

Tightly packed form of DNA that is transcriptionally inactive and generally resistant to transcription.

Euchromatin

Less compact form of DNA that is transcriptionally active and accessible for transcription.

PIC (Preinitiation Complex)

The assembly of various proteins including RNA polymerase at the promoter region, essential for the initiation of transcription.

Activator proteins

Transcription factors that enhance the interaction between RNA polymerase and the promoter, facilitating transcription initiation.

Repressor proteins

Proteins that inhibit gene expression by various mechanisms, including blocking the action of activators or altering chromatin structure.

Co-activators

Proteins that assist activators in enhancing the transcription of a gene by modifying chromatin or recruiting other transcription factors.

Histone acetyltransferase (HAT)

An enzyme that adds acetyl groups to histones, generally associated with the activation of transcription.

Histone deacetylase (HDAC)

An enzyme that removes acetyl groups from histones, typically involved in transcriptional repression.

Chromatin remodeling

The dynamic modification of chromatin architecture to allow access to the DNA for transcription.

Mediator complex

A multi-protein complex that acts as a bridge between activators and the transcription machinery to facilitate transcription.

DNA binding domain

A specific region of a protein that has the structural features necessary to bind to DNA.

Lysine methylation

A post-translational modification where a methyl group is added to lysine residues on histones, affecting transcription regulation.

Bromodomains

Protein domains that recognize acetylated lysine residues, associated with transcriptional activation.

Core promoter

The region of DNA where basic transcription machinery assembles to initiate gene transcription.