Coordinate Regulation of Ribosome and tRNA Biogenesis Controls Hypoxic Injury and Translation.

Area of Science:

• Molecular Biology
• Genetics
• Developmental Biology

Background:

• Protein synthesis requires coordinated regulation of translation machinery components.
• Disruptions in translation can impact lifespan and stress survival.
• Metazoan translational regulation is less understood than in simpler organisms.

Purpose of the Study:

• Investigate mechanisms of translational regulation in C. elegans.
• Identify genes impacting protein synthesis and stress response.
• Define higher-order regulatory mechanisms in metazoans.

Main Methods:

• Genetic screens in C. elegans to identify mutations affecting hypoxic stress survival and developmental arrest.
• Isolation and characterization of genes involved in ribosomal RNA helicase, tRNA biosynthesis, amino acid availability, and ribosome biogenesis.
• Proteomic analysis to assess changes in ribosomal subunits.

Main Results:

• Mutations in ribosomal RNA helicase, tRNA biosynthesis, and amino acid availability genes were identified.
• Genes involved in ribosome biogenesis suppressed developmental arrest in RNA helicase mutants.
• Suppression restored hypoxic sensitivity and protein synthesis in tRNA mutants but not in amino acid availability mutants.
• Reduced tRNA biosynthesis led to homeostatic reduction in ribosomal subunits.

Conclusions:

• A novel higher-order translational regulatory mechanism exists in metazoans.
• Ribosome biogenesis genes interact with tRNA abundance genes.
• This interaction matches global protein synthesis rates with available resources.