Transcriptional Regulation in Eukaryotes

Flashcards related to transcriptional regulation in eukaryotes.

Gene Regulation

The control of gene expression, allowing cells to produce proteins only when needed and in the right amounts.

Erythropoietin

A hormone whose transcription is upregulated under certain conditions such as low oxygen at high altitude or after exercise.

Chromatin Remodeling

The dynamic modification of chromatin architecture to allow access of condensed genomic DNA to regulatory transcription machinery proteins, thereby controlling gene expression.

Nucleosomes

Basic structural units of chromatin, composed of DNA wrapped around histone proteins.

Chromosome Territory

A discrete region that a chromosome occupies in the interphase nucleus.

Transcription Factory

Nuclear sites containing 4-30 RNA polymerase molecules and transcription regulatory molecules, facilitating co-regulation of genes.

Histone Modification

Covalent addition of acetyl, methyl, or phosphate groups to histone tails, influencing chromatin structure and gene expression.

DNA Methylation

Enzyme-mediated addition or removal of a methyl group to DNA, typically at cytosine of CG doublets, repressing transcription.

CpG Islands

Methylatable CpG-rich sequences located in or near promoter regions.

Cis-Acting Elements

DNA sequences on the same chromosome as the gene they regulate, required for accurate transcription (e.g., promoters, enhancers, silencers).

Promoter

Recognition sites for RNA polymerase and transcription factors, essential for minimal transcription.

Enhancer

DNA sequences that increase transcription levels, often conferring time- and tissue-specific gene expression; can be located far from the gene.

Insulator

DNA sequences found between an enhancer and a promoter, blocking some enhancer-promoter interactions to prevent off-target gene regulation.

Silencer

DNA sequences that reduce or block transcription, often conferring time- and tissue-specific gene expression.

Transcription Factors (TF)

Proteins that bind to cis-acting sites to regulate transcription; includes general TFs, activators, and repressors.

Activator

A transcription factor that increases transcription levels.

Repressor

A transcription factor that reduces transcription levels.

Pre-Initiation Complex (PIC)

Assembly of proteins in a specific order that provides a platform for RNA Polymerase II to recognize the start site and initiate transcription.

TFIID

A multisubunit complex composed of TBP and TAFs that binds to the TATA box of the core promoter.

Enhanceosome

A protein complex that interacts with the transcription complex PIC and directs transcription.

Coactivators

Proteins that interact with proteins and enable activators to make contact with promoter-bound factors.

UASG

Upstream Activation Sequence of GAL genes in yeast, where Gal4p binds.