iBRET Screen of the ABCD1 Peroxisomal Network and Mutation-Induced Network Perturbations

Mapping the network of proteins provides a powerful means to investigate
the function of disease genes and to unravel the molecular basis of
phenotypes. We present an automated informatics-aided and bioluminescence
resonance energy transfer-based approach (iBRET) enabling high-confidence
detection of protein−protein interactions in living mammalian
cells. A screen of the ABCD1 protein, which is affected in X-linked
adrenoleukodystrophy (X-ALD), against an organelle library of peroxisomal
proteins demonstrated applicability of iBRET for large-scale experiments.
We identified novel protein–protein interactions for ABCD1
(with ALDH3A2, DAO, ECI2, FAR1, PEX10, PEX13, PEX5, PXMP2, and PIPOX),
mapped its position within the peroxisomal protein–protein
interaction network, and determined that pathogenic missense variants
in ABCD1 alter the interaction with selected binding
partners. These findings provide mechanistic insights into pathophysiology
of X-ALD and may foster the identification of new disease modifiers.