GSG1L-containing AMPA receptor complexes are defined by their spatiotemporal expression, native interactome and...

Area of Science:

• Neuroscience
• Molecular Biology
• Synaptic Plasticity

Background:

• Transmembrane AMPA receptor regulatory proteins (TARPs) and germ cell-specific gene 1-like protein (GSG1L) are auxiliary subunits of AMPA receptors (AMPARs).
• While AMPAR-TARP complexes are well-studied, the function and regulation of GSG1L-containing AMPARs remain less understood.
• GSG1L influences glutamatergic synapse strength and plasticity.

Purpose of the Study:

• To investigate the distinct properties of GSG1L, including its expression pattern, native interactions, and allosteric regulation mechanisms.
• To elucidate the unique signaling role of GSG1L in glutamatergic synapses.

Main Methods:

• Analysis of spatiotemporal expression patterns of GSG1L.
• Characterization of the native interactome of GSG1L.
• Identification and analysis of allosteric sites on GSG1L-associated AMPARs.

Main Results:

• GSG1L exhibits late, region-specific expression during brain development and constitutes approximately 5% of adult AMPAR complexes.
• GSG1L can assemble with TARPs or cornichons (CNIHs), but also functions as a sole auxiliary subunit.
• GSG1L modulates AMPAR kinetics through two distinct allosteric sites, affecting desensitization and recovery from desensitization.

Conclusions:

• GSG1L possesses unique characteristics differentiating it from TARPs in terms of expression, assembly, and allosteric modulation.
• The distinct regulatory mechanisms employed by GSG1L highlight its unique evolutionary trajectory and functional significance in glutamatergic neurotransmission.
• GSG1L plays a specialized role in fine-tuning synaptic transmission within glutamatergic synapses.