On pre-messenger RNA and transcriptions. A review

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Eukaryotic gene expression is a complex process involving the regulation of DNA into functional proteins.
• Understanding the principles of gene expression is crucial for deciphering cellular function and organismal development.
• Previous data provided foundational knowledge, but a comprehensive review integrating old and new findings was needed.

Purpose of the Study:

• To review and synthesize existing and novel data on eukaryotic gene expression.
• To identify and summarize the fundamental principles governing gene expression in eukaryotes.
• To elucidate the mechanistic details and regulatory processes involved in gene expression.

Main Methods:

• Comprehensive literature review integrating historical and recent research findings.
• Analysis of data related to genome organization, transcriptional units, and gene structure.
• Examination of post-transcriptional processing mechanisms, including splicing, capping, and polyadenylation.

Main Results:

• Eukaryotic genomes are organized into transcriptional units (transcriptons) with individual DNA-level activation.
• Transcriptons vary in size and complexity, containing coding and regulatory sequences, often in sub-genic blocks.
• Gene expression involves pre-messenger RNA (pre-mRNA) processing, including splicing, chemical modifications, and translation into polypeptides or polyproteins.

Conclusions:

• Gene expression in eukaryotes follows a few core principles, with significant mechanistic diversity.
• The functional gene is often assembled post-transcriptionally from genomic subunits via processing.
• Post-transcriptional regulation plays a critical role, involving multiple steps from pre-mRNA to functional mRNA and proteins.