Evolutionary plasticity in the innate immune function of Akirin

Area of Science:

• Molecular Biology
• Immunology
• Developmental Biology

Background:

• Eukaryotic gene expression involves transcription factors and chromatin remodelers.
• The conserved protein Akirin links chromatin remodelling complexes with transcription factors like NFκB in insects and mammals.
• Akirin is essential for defense gene expression in Caenorhabditis elegans, even without NFκB.

Purpose of the Study:

• To investigate the role and molecular interactions of Akirin in Caenorhabditis elegans innate immunity.
• To identify the specific partners of Akirin in C. elegans gene regulation.

Main Methods:

• Reverse genetics was employed to study gene function.
• Biochemical methods were used to identify protein complexes.

Main Results:

• Akirin forms a physical complex with NuRD proteins and the POU-class transcription factor CEH-18 in C. elegans.
• This interaction is essential for the expression of defense genes in the epidermis.
• Akirin's role as a bridge between chromatin remodelers and transcription factors is conserved, but its partners are lineage-specific.

Conclusions:

• Akirin's function in bridging chromatin remodelers and transcription factors is conserved across species.
• The specific protein partners of Akirin in C. elegans (NuRD and CEH-18) differ from those in mammals and insects.
• This study advances the understanding of innate immune gene regulation and the evolution of signaling pathways in C. elegans.