Clustered protocadherin cis-interactions are required for combinatorial cell-cell recognition underlying neuronal...

Area of Science:

• Neuroscience
• Molecular Biology
• Developmental Biology

Background:

• Clustered protocadherins (cPcdh) are crucial for neuronal self-recognition and self-avoidance in the developing brain.
• Neuronal wiring relies on precise recognition, mediated by a large repertoire of cPcdh isoforms.
• The mechanism by which a single cPcdh isoform mismatch prevents recognition remains poorly understood.

Purpose of the Study:

• To elucidate how single mismatched clustered protocadherin (cPcdh) isoforms between neighboring neurons block erroneous recognition.
• To investigate the role of cPcdh cis and trans interactions in neuronal self-recognition.
• To understand the impact of cPcdh assembly organization on neuronal self/non-self-discrimination.

Main Methods:

• Conducted systematic cell aggregation experiments to analyze cPcdh interactions.
• Utilized computer simulations to model cPcdh organization and binding dynamics.
• Investigated the effects of abolishing cis cPcdh interactions on trans binding specificity.

Main Results:

• Abolishing cis cPcdh interactions led to a complete loss of specific trans combinatorial binding between cells.
• cPcdh organization into linear array oligomers enhances self-recognition by increasing cis and trans complex stability.
• Mismatched cPcdh isoforms between cells significantly reduce the concentration and stability of trans complexes.

Conclusions:

• cPcdh cis interactions are essential for establishing specific trans recognition between neurons.
• The oligomeric organization of cPcdh molecules is critical for robust neuronal self-recognition.
• The sensitivity of cPcdh complexes to isoform mismatches provides a mechanism for precise neuronal self/non-self-discrimination.