Codon optimality is a major determinant of mRNA stability.

Area of Science:

• Molecular Biology
• Gene Expression Regulation
• RNA Metabolism

Background:

• mRNA degradation is a key regulatory step in gene expression.
• The factors contributing to varying mRNA half-lives remain incompletely understood.
• Previous research has identified major mRNA turnover pathways.

Purpose of the Study:

• To investigate the role of codon optimality in determining mRNA stability.
• To explore the connection between translation elongation and mRNA decay.
• To understand how codon composition influences mRNA levels and protein production.

Main Methods:

• Genome-wide RNA decay analysis was performed.
• Synonymous codon substitutions (optimal to non-optimal and vice versa) were introduced into mRNAs.
• Ribosome translocation dynamics were assessed in relation to codon usage.

Main Results:

• Stable mRNAs were found to be enriched in optimal codons.
• Unstable mRNAs predominantly contained non-optimal codons.
• Substitution of codons significantly altered mRNA stability, with optimal codons increasing stability and non-optimal codons decreasing it.
• Codon optimality was shown to impact ribosome translocation, linking translation and decay.
• Optimal codon content explained coordinated mRNA stabilities in functionally related genes.

Conclusions:

• Codon optimality is a critical determinant of mRNA stability.
• This mechanism allows for fine-tuning of mRNA and protein levels.
• Codon usage directly influences the regulation of gene expression through mRNA decay rates.