[Intercellular channels in animals].

Area of Science:

• Cell biology
• Evolutionary biology
• Biochemistry

Context:

• Gap junctions facilitate intercellular communication in multicellular animals (Metazoa).
• Traditionally, connexins (chordates) and pannexins (chordates and invertebrates) were identified as the primary protein families forming these junctions.
• Recent genomic data challenge this established understanding of gap junction protein diversity.

Purpose:

• To investigate the diversity of proteins forming gap junctions across different animal taxa.
• To re-evaluate the evolutionary conservation of connexins and pannexins in gap junction formation.
• To identify alternative protein families involved in gap junction assembly.

Summary:

• Connexins are found exclusively in chordates, while pannexins are present in both chordates and invertebrates.
• Exceptions exist, such as the Chordate lancelet, which appears to possess only pannexins.
• Emerging evidence suggests some metazoans utilize entirely different, yet unidentified, proteins to construct functional gap junctions.

Impact:

• This research expands our understanding of the molecular mechanisms underlying cell-to-cell communication in animals.
• It highlights the evolutionary plasticity of gap junction proteins.
• Identifies novel protein families potentially involved in intercellular transport and signaling, opening new avenues for research.