Molecular basis of neurodevelopmental disorders caused by pathogenic variants of PIDD

Area of Science:

• Cellular biology
• Molecular mechanisms of disease
• Apoptosis and cell death pathways

Background:

• PIDDosome formation and caspase-2 activation are crucial for apoptosis following genotoxic stress.
• Defects in caspase-2 activation lead to neurodevelopmental disorders and intellectual disability.
• Specific mutations (R815W, R862W, Q863stop) in PIDD are linked to these disorders, but the underlying mechanisms are unclear.

Purpose of the Study:

• To elucidate the molecular mechanisms behind the pathogenesis caused by PIDD DD pathogenic variants (R815W, R862W, Q863stop).
• To investigate how these PIDD mutations affect PIDDosome formation and caspase-2 activation.

Main Methods:

• Analysis of molecular mechanisms underlying PIDD DD pathogenic variants.
• Investigating the interaction between PIDD and RAIDD in the context of these mutations.

Main Results:

• The studied PIDD mutations (R815W, R862W, Q863stop) were found to inhibit the interaction between PIDD and RAIDD.
• This disrupted interaction impairs PIDDosome assembly and subsequent caspase-2 activation.

Conclusions:

• The pathogenic variants of PIDD DD disrupt the PIDD-RAIDD interaction, leading to impaired PIDDosome formation and caspase-2 activation.
• This molecular defect provides a mechanistic link between PIDD mutations and the pathogenesis of neurodevelopmental disorders and intellectual disability.