The genetic landscape of a physical interaction

Area of Science:

• Human genetics
• Evolutionary biology
• Molecular biology

Background:

• Understanding how genetic mutations combine to alter phenotypes is crucial.
• Most genetic variation arises from point mutations with unpredictable effects.
• Previous studies primarily used gene deletions to map genetic interactions.

Purpose of the Study:

• To develop a novel method for quantifying the effects of point mutations on protein complex formation.
• To systematically map genetic interactions within the AP-1 transcription factor complex.
• To investigate the relationship between physical interactions and genetic interactions.

Main Methods:

• Development of a sequencing-based protein interaction assay called deepPCA.
• Quantification of >120,000 pairs of point mutations affecting FOS-JUN complex formation.
• Classification of genetic interactions into thermodynamic and structural categories.

Main Results:

• Abundant genetic interactions were observed both in cis and in trans within the AP-1 complex.
• Thermodynamic interactions could be predicted using a three-parameter global model.
• Structural interactions were identified between proximally located residues.

Conclusions:

• Physical interactions between proteins generate quantitatively predictable genetic interactions.
• DeepPCA provides a powerful tool for studying the effects of point mutations on protein complexes.
• This work advances the understanding of genetic variation and its phenotypic consequences.