Orb2 enables rare-codon-enriched mRNA expression during Drosophila neuron differentiation.

Area of Science:

• Molecular Biology
• Neuroscience
• Genetics

Background:

• Cell- and tissue-specific protein expression is controlled by codon optimality.
• Understanding how gene expression is regulated during neural stem cell differentiation is crucial.

Approach:

• Utilized codon-modified reporters to assess protein expression during Drosophila neural stem cell differentiation.
• Conducted a candidate screen to identify regulators of rare-codon-dependent expression.
• Employed RNA sequencing to analyze Orb2-upregulated mRNAs in the brain.
• Investigated the functional significance of rare-codon enrichment in specific genes.

Key Points:

• Drosophila neural stem cell differentiation into neurons promotes protein expression from rare-codon-enriched genes.
• The cytoplasmic polyadenylation element binding (CPEB) protein Orb2 was identified as a positive regulator of rare-codon expression in neurons.
• Orb2-upregulated mRNAs in the brain exhibit a rare-codon bias and contain Orb2 binding sites.
• Rare-codon enrichment is vital for the expression control and social behavior function of the metabotropic glutamate receptor (mGluR).

Conclusions:

• Neural stem cell differentiation triggers a shift in genetic code regulation.
• This shift enables critical mRNA and protein expression necessary for neuronal function.
• Orb2 acts as a key molecular mechanism in this differentiation-dependent regulatory process.