Phase separated condensates of ATRX regulate neural progenitor identity

Area of Science:

• Cell Biology
• Neuroscience
• Genetics

Background:

• Mutations in the ATRX gene cause alpha-thalassemia X-linked intellectual disability (ATR-X) syndrome.
• The ATRX protein plays a role in chromatin structure, but its precise functions in neurodevelopment are not fully understood.

Purpose of the Study:

• To investigate the role of ATRX in human neural progenitor cell (hNPC) fate determination.
• To explore the mechanism of ATRX function, particularly its potential involvement in liquid-liquid phase separation (LLPS).

Main Methods:

• Utilized human neural progenitor cells (hNPCs).
• Investigated the role of the intrinsically disordered region (IDR) of ATRX in condensate formation.
• Examined ATRX localization at super-enhancers (SEs).
• Assessed the impact of disrupted ATRX condensates on gene expression and neuronal differentiation.

Main Results:

• ATRX forms dynamic condensates in hNPCs through LLPS, mediated by its IDR.
• These ATRX condensates are essential for recruiting co-activators and localizing ATRX to SEs, linking compartmentalization to transcriptional regulation.
• Disruption of ATRX condensates alters gene expression and impairs neuronal differentiation, affecting hNPC identity.

Conclusions:

• ATRX phase separation is a key mechanism regulating gene networks vital for hNPC identity and neurodevelopment.
• This study expands the understanding of ATRX function beyond chromatin structure, highlighting LLPS as a critical regulatory process.
• Dysregulation of ATRX and its phase-separation ability may contribute to ATR-X syndrome and other neurodevelopmental disorders.