Gene Regulation and Chromatin Structure

Vocabulary flashcards covering eukaryotic gene expression, chromatin modifications, transcriptional elements, and post-transcriptional mechanisms.

Transcription Factor

A regulatory protein that directly binds to DNA, differentiating it from a coactivator.

Coactivator

A protein that regulates transcription but does not directly bind to DNA.

Enhancer

A regulatory DNA sequence whose characteristics do not include reducing transcription.

Galactose

The environmental signal that facilitates the regulation of GAL4.

Chromatin

A cellular structure whose role in transcriptional regulation is to act as a substrate for reversible changes.

Euchromatin

The chromatin structure that allows genes to be transcriptionally active.

Unmethylated CpG Islands

Regions at promoters that are associated with open chromatin and active transcription.

Position Effect Variegation

A phenomenon that occurs as a result of chromosomal rearrangement.

Parental Imprinting

An epigenetic phenomenon where the consequence is that only one copy of a gene is expressed.

Promoter

A DNA sequence located near the start of a gene that RNA polymerase binds to initiate transcription.

Repressor

A transcription factor that prevents mRNA synthesis by binding to the operator of a gene.

Insulator

An element that disrupts the signal between enhancers and promoters.

Regulatory Gene

A gene that controls the expression of one or more genes by promoting or inhibiting transcription.

Inducer

A small molecule that activates transcription by inhibiting the action of a repressor protein.

Operator

A short sequence of DNA located near the promoter region that is recognized by a repressor protein.

CpG Island Methylation

A modification that causes changes in chromatin structure and represses promoter activity.

RNA Interference

A regulatory mechanism in which a siRNA and the transcript it targets are transcribed from the same gene.

Transcription Apparatus Activity

A regulatory stage where the initiation of transcription occurs upon the binding of TFIID at the TATA box.

Initiation of Translation

A stage of gene regulation where limited availability of initiation factors prevents the translation of mRNA.

RNA Processing

A mechanism in which the $3'$ end can be cleaved to produce different transcript lengths before the addition of the poly-A tail.

Histone Acetyltransferases

Enzymes that attach acetyl groups to the N-terminus of histones, resulting in the activation of transcription.

Histone Methylation

A modification occurring at different amino acids of histones that can either activate or inactivate transcription.