Defects in syntabulin-mediated synaptic cargo transport associate with autism-like synaptic dysfunction and social...

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Synaptic formation and maintenance rely on long-distance protein transport from the soma to synapses.
• Impaired neuronal transport is a potential factor in neurodevelopmental disorders like autism.
• Syntabulin functions as a motor adapter, linking kinesin-1 motors to presynaptic cargos.

Purpose of the Study:

• To investigate the role of syntabulin-mediated transport in synaptic function and autism-like behaviors.
• To determine if defects in syntabulin lead to synaptic dysfunction and social behavioral abnormalities.
• To examine the impact of a human syntabulin variant found in an autism patient.

Main Methods:

• Utilized conditional syntabulin knockout (stb cKO) mice to study gene function.
• Analyzed synaptic structure, transmission, and plasticity in stb cKO neurons.
• Assessed social recognition, communication, stereotypic behavior, and spatial learning in stb cKO mice.
• Investigated the functional impact of a human STB-R178Q variant in stb cKO neurons.

Main Results:

• Syntabulin deficiency in mice resulted in impaired presynaptic cargo transport, reduced synapse density, and altered synaptic transmission and plasticity.
• stb cKO mice displayed core autism-like traits, including social deficits, stereotypic behaviors, and impaired learning.
• A human missense variant (STB-R178Q) found in an autism patient lost its kinesin-1 binding capacity and failed to rescue synaptic deficits in stb cKO neurons.

Conclusions:

• Defects in syntabulin-mediated transport are a key synaptic mechanism underlying autism-like synaptic dysfunction and behavioral abnormalities.
• Reduced transport of synaptic cargos contributes to impaired synaptic maintenance and plasticity, leading to autism-associated behaviors.
• The study establishes a direct link between syntabulin function, synaptic integrity, and autism spectrum disorder.