Regulation of neuronal morphogenesis by 14-3-3epsilon (Ywhae) via the microtubule binding protein, doublecortin

Area of Science:

• Genetics
• Neuroscience
• Cell Biology

Background:

• 17p13.3 microduplication syndrome is a genetic disorder associated with autism spectrum disorder (ASD).
• A minimal critical region for this syndrome exclusively contains the 14-3-3ε gene, suggesting its overexpression contributes to ASD.
• The precise cellular mechanisms linking 14-3-3ε to ASD remain unclear.

Purpose of the Study:

• To investigate the role of 14-3-3ε in the cellular pathology of 17p13.3 microduplication syndrome.
• To elucidate the molecular mechanisms by which 14-3-3ε affects neuronal development, specifically neurite formation.
• To establish a link between 14-3-3ε function and the pathogenesis of ASD in this syndrome.

Main Methods:

• In vitro and in vivo experiments were conducted to study protein interactions and cellular processes.
• Utilized techniques to examine the binding of 14-3-3ε to doublecortin and its effect on protein degradation.
• Employed 14-3-3ε flox mice to analyze the in vivo consequences of gene deficiency on neurite formation.

Main Results:

• 14-3-3ε was found to bind to doublecortin, a microtubule-binding protein, thereby inhibiting its degradation.
• Overexpression of 14-3-3ε was shown to disrupt neurite formation by impeding microtubule invasion into developing neurites.
• Knockdown of doublecortin rescued the neurite formation defects caused by 14-3-3ε overexpression.
• Conversely, 14-3-3ε deficiency in mice led to an increase in neurite formation.

Conclusions:

• The study provides the first evidence of cellular pathology in 17p13.3 microduplication syndrome.
• Overexpressed 14-3-3ε disrupts neurite formation by interfering with the microtubule-binding protein doublecortin.
• These findings highlight 14-3-3ε as a key player in the pathogenesis of ASD associated with 17p13.3 microduplication syndrome.