The pleiotropic functions of Pri smORF peptides synchronize leg development regulators

Area of Science:

• Developmental Biology
• Molecular Biology
• Genetics

Background:

• Small open reading frame (smORF) peptides are a recently identified class of proteins with largely unknown functions.
• Hundreds of putative smORF peptides are expressed in Drosophila imaginal leg discs, suggesting roles in development.

Purpose of the Study:

• To investigate the function of smORF peptides, particularly the pioneer (Pri) peptides, in Drosophila leg development.
• To elucidate the role of Ubr3 in mediating Pri peptide function during leg development.

Main Methods:

• Bioinformatic analysis to identify putative smORF peptides.
• Functional screening in Drosophila leg discs to identify peptides involved in morphogenesis.
• Genetic analysis to study the interaction between Pri peptides and Ubr3.

Main Results:

• Pri peptides are involved in both leg patterning and cell survival.
• During larval stages, Pri activates tarsal transcriptional programs and Notch/EGFR signaling independently of Ubr3.
• At the larval-pupal transition, Pri peptides cooperate with Ubr3 to ensure cell survival and leg morphogenesis.

Conclusions:

• Pri peptides exhibit both Ubr3-dependent and independent functions, highlighting their pleiotropy.
• The smORF peptide family represents a significant source of novel developmental regulators.
• smORF peptides play crucial roles in orchestrating complex developmental processes like leg formation.