GCN sensitive protein translation in yeast.

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Protein translation levels are influenced by both the translational machinery and mRNA sequence features.
• A notable three-nucleotide periodicity, characterized by GCN codons, is observed in mRNA Open Reading Frames (ORFs).
• This periodicity is pronounced in the ramp region of highly expressed genes and near non-standard start sites in Saccharomyces cerevisiae.

Purpose of the Study:

• To investigate the impact of ramp GCN periodicity on translation efficiency.
• To explore the molecular mechanisms underlying GCN-mediated translation regulation.

Main Methods:

• Analysis of mRNA sequences in Saccharomyces cerevisiae.
• Testing edited mRNA ramp sequences with altered GCN periodicity in test genes (SKN7, HMT1).
• Molecular Dynamics analysis of ribosome-mRNA interactions.
• Integration of expression studies with large-scale reporter assays.

Main Results:

• Increased conformance to the (GCN)n pattern significantly decreased translation.
• Disrupting the (GCN)n pattern had neutral or positive effects on translation.
• A specific mRNA-ribosome interaction surface (C1054-A1196-R146) preferentially interacts with GCN codons.

Conclusions:

• The GCN periodicity in mRNA ramp regions plays a regulatory role in protein translation.
• The CAR interaction surface acts as a modulator, potentially accelerating or braking ribosome translation.
• This finding offers insights into mRNA sequence-driven regulation of gene expression.