Pathogenic mutations of human phosphorylation sites affect protein-protein interactions

Area of Science:

• Biochemistry
• Molecular Biology
• Genetics

Background:

• Intrinsically disordered regions (IDRs) lack defined 3D structures but are crucial for biological functions.
• Short linear motifs (SLiMs) within IDRs mediate protein-protein interactions (PPIs), often regulated by phosphorylation.
• Pathogenic mutations in IDRs are common and can disrupt PPIs, contributing to disease.

Purpose of the Study:

• To investigate how disease-associated mutations affecting phosphorylation sites in IDRs impact protein-protein interactions.
• To understand the molecular mechanisms underlying pathogenesis caused by mutations in IDRs.

Main Methods:

• Peptide-based interaction proteomics was used to analyze 36 disease-associated mutations.
• Investigated differences in interactomes between phosphorylated and non-phosphorylated peptides.
• Focused on a specific mutation in GATAD1 and its interaction with 14-3-3 proteins.

Main Results:

• Significant differences in protein interactomes were observed between phosphorylated and non-phosphorylated peptides, often due to disrupted phosphorylation-dependent SLiMs.
• A serine phosphorylation site mutation in GATAD1 was found to disrupt interactions with 14-3-3 proteins.
• 14-3-3 binding to GATAD1 was shown to affect its nucleocytoplasmic transport by masking a nuclear localization signal.

Conclusions:

• Pathogenic mutations in human phosphorylation sites within IDRs can significantly alter protein-protein interactions.
• These alterations provide insights into the molecular mechanisms of disease pathogenesis.
• Understanding these disruptions is crucial for deciphering disease mechanisms and developing therapeutic strategies.