Lec 18 Transcriptional and Posttranscriptional Regulation in Eukaryotes

This set of flashcards covers key terms and concepts related to transcriptional and posttranscriptional regulation of gene expression in eukaryotic cells.

Enhancer

A regulatory DNA element that increases the transcription of a gene.

Silencer

A regulatory DNA element that represses the transcription of a gene.

Basal transcription complex

A multi-protein complex that assembles at the promoter region to initiate transcription.

Regulatory transcription factors

Proteins that bind to specific DNA sequences to regulate transcription.

Epigenetics

The study of heritable changes in gene expression that do not involve modifications to the DNA sequence.

RNA processing

The modifications made to a primary RNA transcript to produce a mature mRNA.

Alternative splicing

A process that allows a single gene to produce multiple mRNA isoforms by including or excluding certain exons.

miRNA (microRNA)

Short RNA molecules that regulate gene expression by binding to mRNA and inhibiting translation.

siRNA (small interfering RNA)

Short double-stranded RNA molecules that can cause degradation of specific mRNA molecules.

Proteasome

A protein complex that degrades ubiquitin-tagged proteins.

Ubiquitin

A small protein that tags other proteins for degradation by the proteasome.

Phosphorylation

The addition of a phosphate group to a protein, which can change its activity and function.

Transcription start site

The location on the DNA where RNA polymerase begins transcription.

Posttranslational modification

Chemical modifications after translation that affect protein function and stability.

Mediator complex

A multi-protein complex that mediates the interactions between transcription factors and RNA polymerase.

Co-activator

A protein that increases gene expression by binding to an enhancer or a transcription factor.

Co-repressor

A protein that inhibits gene expression by binding to a silencer or a transcription factor.

RNA-induced silencing complex (RISC)

A protein complex that incorporates short RNA molecules to regulate gene expression.

DNA methylation

The addition of methyl groups to DNA, often leading to gene silencing.

Chromatin remodeling

Structural changes in chromatin that make DNA more or less accessible for transcription.

HAT (Histone Acetyltransferase)

An enzyme that adds acetyl groups to histones, usually resulting in gene activation.

HDAC (Histone Deacetylase)

An enzyme that removes acetyl groups from histones, usually leading to gene repression.

3' UTR (Untranslated Region)

The region of mRNA downstream of the coding sequence that can regulate mRNA stability and translation.

Orf (Open Reading Frame)

A sequence of DNA that has the potential to be translated into a protein.

Nuclear pore

Complexes that regulate the transport of proteins and RNA between the nucleus and cytoplasm.