Cycloheximide-resistant ribosomes reveal adaptive translation dynamics in C. elegans

Area of Science:

• Molecular Biology
• Genetics
• Developmental Biology

Background:

• Protein translation regulation is crucial for cellular functions and development.
• The precise mechanisms by which disruptions in translation elongation impact these processes are not fully understood.

Purpose of the Study:

• To investigate the consequences of inhibiting translation elongation on cellular processes and development.
• To identify genetic tools for studying translation regulation using CRISPR-based genome editing.

Main Methods:

• Identified a cycloheximide (CHX)-resistant mutation (P55Q) in ribosomal protein RPL-36A in Caenorhabditis elegans.
• Utilized the RPL-36A(P55Q) mutation as a selection marker for CRISPR-based genome editing of ribosomal protein genes.
• Performed ribosome profiling in L4-stage heterozygotes to analyze translation dynamics under partial CHX inhibition.

Main Results:

• The RPL-36A(P55Q) mutation confers complete CHX resistance and acts as a dominant selectable marker for genome editing.
• Partial inhibition of translation elongation led to increased start-codon occupancy and reduced disome formation.
• Selective changes in translation efficiency (TE) were observed, with decreased expression of nucleolar/P-granule components and increased expression of oocyte development genes, leading to premature oocyte development.

Conclusions:

• Partial inhibition of translation elongation disrupts developmental timing across tissues by altering translation efficiency.
• Canonical stress response pathways are not activated by chronic partial translation elongation inhibition.
• The RPL-36A(P55Q) mutation is a valuable tool for studying essential gene function and translation regulation.