Lecture on Epigenetics and Gene Regulation

Flashcards covering key vocabulary and definitions from the lecture on gene regulation, transcription, and regulatory elements.

Central Dogma

The central dogma of molecular biology describes the flow of genetic information from DNA to RNA (transcription) and then from RNA to protein (translation).

Transcription

The process by which the information in a strand of DNA is copied into a new molecule of messenger RNA (mRNA). In eukaryotes, this takes place in the nucleus and is facilitated by RNA polymerase II.

Translation

The process by which ribosomes in the cytoplasm or ER synthesize proteins after the process of transcription of DNA to RNA in the cell's nucleus.

Eukaryotic Transcription

The process of transcribing DNA into RNA in eukaryotic organisms, which takes place in the nucleus and is more complex than in bacteria due to the presence of a nucleus and chromatin structure.

Gene Regulation

The process of controlling the timing, location, and level to which genes are expressed, crucial for cell differentiation, tissue organization, and responses to stimuli.

Constitutively Expressed Genes

Genes that are always expressed because they are needed in every cell type for basic cellular functions (e.g., RNA polymerase II).

Coding Region

The region of DNA that contains the protein-coding information, including exons and introns, which undergoes splicing to produce the final mRNA.

Regulatory Region

The non-coding region of DNA that controls gene expression, often located upstream of the coding region, and can span large distances, influencing transcription through various elements.

Cis-Acting Regulatory Elements

DNA sequences within a gene's regulatory region that affect gene expression on the same DNA molecule.

Trans-Acting Factors

Proteins that bind to cis-regulatory elements to control gene expression. These proteins are encoded by genes located elsewhere in the genome.

Transcription Start Site (TSS)

The specific location on DNA where RNA synthesis begins. It is a key region for the initiation of gene transcription.

Proximal Elements

Regulatory sequences located close to the transcription start site (within the first kilobase), influencing the recruitment and stability of RNA polymerase.

Distal Elements

Regulatory sequences located far away from the transcription start site (kilobases away), such as enhancers and silencers, which modulate gene expression.

Core Promoter

The region immediately upstream of the transcription start site that is essential for transcription initiation. It includes elements like the TATA box.

TATA Box

A conserved DNA sequence (typically TATAAA) in the core promoter region that serves as a binding site for the TATA-binding protein (TBP), which is crucial for initiating transcription.

TATA-Binding Protein (TBP)

A protein that recognizes and binds to the TATA box, initiating the recruitment of RNA polymerase II and other transcription factors.

GC Box

A proximal promoter element with a high GC content, associated with constitutively expressed genes.

CAT Box

A proximal promoter element involved in the regulation of non-constitutive genes that respond to environmental cues.

Enhancers

Distal regulatory elements that enhance gene expression by interacting with the core promoter, often located far away from the transcription start site.

Silencers

Distal regulatory elements that repress gene expression by preventing RNA polymerase II recruitment or displacing proteins at the core regulatory site.