Mutation near the binding interfaces at α-hemoglobin stabilizing protein is highly pathogenic.

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Free alpha-hemoglobin aggregation generates reactive oxygen species during erythroid cell development.
• Alpha hemoglobin stabilizing protein (AHSP) acts as a chaperone to prevent this harmful aggregation.
• Mutations in the AHSP gene can disrupt its interaction with globin proteins, potentially impacting erythroid cell function.

Purpose of the Study:

• To identify deleterious single nucleotide polymorphisms (nsSNPs) in the AHSP gene.
• To evaluate the pathogenic effects of these nsSNPs on AHSP-globin interactions.
• To investigate the impact of specific AHSP mutations on protein stability and interactions with other proteins like HBA2 and KLF1.

Main Methods:

• Utilized multiple computational tools (PROVEAN, SIFT, SNAP2, SNPs&GO, PolyPhen, FATHMM, PANTHER, VEST) to predict the pathogenicity of nsSNPs in AHSP.
• Performed protein-protein interaction analysis to assess the effect of mutations on AHSP's binding capabilities.
• Analyzed changes in binding energies associated with AHSP and HBA1 gene mutations.

Main Results:

• The V56G substitution in AHSP was consistently identified as the most pathogenic nsSNP across all computational tools.
• This V56G mutation occurs near a hotspot, forms an extra helix, and significantly disrupts the interaction between AHSP and proteins like HBA2 and KLF1.
• Significant variations in binding energies were observed for mutations in the AHSP and/or HBA1 genes.

Conclusions:

• The V56G mutation in AHSP (p.val56Gly) is a highly pathogenic variant with significant implications for AHSP-globin interactions.
• This mutation disrupts normal protein interactions, potentially contributing to erythroid cell dysfunction.
• The study recommends further experimental validation of the p.val56Gly mutation in wet lab settings.