Phosphorylation of 53BP1 by ATM enforce neurodevelopmental programs in cortical organoids

Area of Science:

• Molecular Biology
• Developmental Neuroscience
• Genetics

Background:

• 53BP1 (Tumor suppressor p53-binding protein 1) is a key DNA damage response factor with emerging roles in gene regulation, tumor suppression, and neural development.
• The precise mechanisms regulating 53BP1's function in gene expression, particularly during neural development, remain largely uncharacterized.

Approach:

• Investigated the role of 53BP1 phosphorylation by ATM (Ataxia-Telangiectasia Mutated) in human cortical organoid development.
• Utilized phospho-specific antibodies and genetic manipulation to analyze the impact of 53BP1-serine 25 phosphorylation on neural progenitor cell proliferation and neuronal differentiation.

Key Points:

• ATM-dependent phosphorylation of 53BP1 at serine 25 is essential for neural progenitor cell proliferation and neuronal differentiation in cortical organoids.
• Phosphorylation dynamics of 53BP1 control its target genes, influencing neuronal differentiation, cellular stress responses, and apoptosis.
• ATM also phosphorylates other critical factors involved in neuronal differentiation, cytoskeletal organization, p53 regulation, and key signaling pathways (BDNF, WNT).

Conclusions:

• 53BP1 and ATM act in concert to regulate essential genetic programs governing human cortical development.
• These findings elucidate a novel regulatory mechanism for 53BP1 in neural development and highlight the critical role of ATM signaling in this process.