REGULATION OF EUKARYOTIC GENE EXPRESSION

The molecular mechanisms that operate to regulate gene expression in eukaryotes vary greatly from that in prokaryotes. This is basically because of the following reasons:

• The eukaryotic genome is highly complex and more condensed than the prokaryotes.
• Eukaryotes have more chromosomes than the prokaryotic systems.
• Eukaryotes exhibit more cellular compartmentalization than the prokaryotes.
• Eukaryotic mRNAs have longer half-life than prokaryotic mRNAs.
• A large portion of eukaryotic genome is non-coding.

There are six control points of gene regulation in eukaryotes. They are:

1. Regulation at transcription level,
2. Regulation at post-transcriptional modification level,
3. Regulation of the nuclear export of mRNA,
4. Stability of the mRNA,
5. Regulation at translational level and
6. Regulation of the chromatin structure.