Structural and Intermolecular Associations Between Connexin36 and Protein Components of the Adherens...

Area of Science:

• Neuroscience
• Cell Biology
• Structural Biology

Background:

• Gap junctions and adherens junctions have known relationships in peripheral tissues.
• Their intimate connections in the central nervous system (CNS) remain less understood.
• Adherens junctions are often found near neuronal gap junctions in the CNS.

Purpose of the Study:

• To investigate the localization of adherens junction proteins relative to connexin36 (Cx36)-containing neuronal gap junctions in the CNS.
• To explore the potential structural and functional interactions between these two types of cell junctions.

Main Methods:

• Immunofluorescence microscopy was used to visualize protein localization.
• The study examined several brain regions, focusing on primary afferent neurons in the mesencephalic trigeminal nucleus (MesV).
• Experiments included comparisons in wild-type and connexin36 null mice.

Main Results:

• Adherens junction proteins (N-cadherin, nectin-1, α-catenin, β-catenin) and associated proteins (zonula occludens-1, AF6/afadin) were found to localize near or overlap with Cx36 gap junctions.
• This colocalization was observed in multiple brain regions.
• Adherens junction components were present even in the absence of Cx36, indicating their maintenance.

Conclusions:

• Results support the concept of a multi-molecular composition of electrical synapses, forming an adherens junction-neuronal gap junction complex.
• This complex suggests potential protein-protein interactions influencing electrical synapse structure and function.
• Intracellular signaling pathways may regulate the assembly, maintenance, and turnover of this complex, impacting neuronal communication dynamics.