Unconventional codon usage bias mediates mRNA translational dynamics in macrophages

Area of Science:

• Immunology
• Molecular Biology
• Genetics

Background:

• Transcriptional regulation in macrophages is understood, but translational control mechanisms are not.
• Macrophages need precise regulation to respond to environmental changes.

Purpose of the Study:

• Investigate mRNA translation dynamics in mouse macrophages during LPS exposure.
• Elucidate phase-specific translational regulation and its mechanisms in macrophage polarization.

Main Methods:

• Studied mRNA translation dynamics in mouse macrophages under varying LPS exposure durations.
• Analyzed 5' UTR upstream translation and codon usage bias in macrophage mRNAs.

Main Results:

• Observed phase-specific translational regulation during macrophage polarization.
• Found increased inflammatory mediator synthesis and suppressed cell cycle gene expression early on.
• Identified upstream translation in 5' UTRs of cell cycle genes causing arrest.
• Discovered a unique AU codon preference in macrophages, enhancing translation efficiency for cell cycle restoration.

Conclusions:

• uORF translation and codon usage bias are key to translational regulation in macrophage polarization.
• These mechanisms control inflammatory responses and cell cycle dynamics.
• Macrophage-specific codon optimization presents a therapeutic strategy for immune modulation.