Lecture 24 Eukaryotic Gene Regulation

Flashcards reviewing the key concepts of eukaryotic gene regulation, including chromatin structure and histone acetylation during transcription.

Eukaryotic Gene Regulation Complexity

Regulation of genes in eukaryotes is more complex than in prokaryotes, especially in multicellular eukaryotes due to different cell types requiring different proteins.

Cellular Differentiation

Different cell types have the same set of genes inherited through mitosis but express different proteins necessary for their specific functions.

Gene Expression

The process where information from a gene is used to make a functional protein.

High Gene Expression

If a gene is more highly expressed in one cell compared to another, the cell will likely have more mRNA (produced by transcription) and more protein molecules (produced by translation).

Gene Expression Regulation Points

Key points where gene expression is regulated include chromatin structure, transcription, RNA processing, mRNA transport, translation, protein processing, protein transport, and mRNA/protein degradation.

Chromatin Structure Importance

The accessibility of genes to transcription machinery is influenced by the chromatin structure (how tightly or loosely packed the DNA is).

Histone Proteins

Positively charged proteins that bind to negatively charged DNA to form the chromatin complex.

Euchromatin

Transcriptionally active form of chromatin that is less tightly packed.

Heterochromatin

Tightly packed form of chromatin that is not usually transcriptionally active.

Histone Tails

Amino acid sequences sticking out of histone proteins available for chemical modification.

Histone Acetylation

Addition of acetyl groups to histone tails neutralizes their positive charge, loosening the chromatin structure and making genes more available for transcription.

Effect of Acetylation

When histones are acetylated the histones will bind less tightly to the DNA, which loosens chromatin structure, and makes genes more available for transcription.