AAK1 Identified as an Inhibitor of Neuregulin-1/ErbB4-Dependent Neurotrophic Factor Signaling Using Integrative Chemical Genomics and Proteomics

SummaryTarget identification remains challenging for the field of chemical biology. We describe an integrative chemical genomic and proteomic approach combining the use of differentially active analogs of small molecule probes with stable isotope labeling by amino acids in cell culture-mediated affinity enrichment, followed by subsequent testing of candidate targets using RNA interference-mediated gene silencing. We applied this approach to characterizing the natural product K252a and its ability to potentiate neuregulin-1 (Nrg1)/ErbB4 (v-erb-a erythroblastic leukemia viral oncogene homolog 4)-dependent neurotrophic factor signaling and neuritogenesis. We show that AAK1 (adaptor-associated kinase 1) is a relevant target of K252a, and that the loss of AAK1 alters ErbB4 trafficking and expression levels, providing evidence for a previously unrecognized role for AAK1 in Nrg1-mediated neurotrophic factor signaling. Similar strategies should lead to the discovery of novel targets for therapeutic development.

Graphical AbstractFigure optionsDownload full-size imageDownload high-quality image (300 K)Download as PowerPoint slideHighlights► Neurotrophic factor signaling through Nrg1/ErbB4 is involved in neuritogenesis ► K252a was identified as a potentiator of Nrg1-mediated neuritogenesis ► Quantitative proteomics identified AP2 adaptor-associated kinase 1 (AAK1) as a relevant target of K252a ► Inhibition of AAK1 reveals its role in both ErbB4 trafficking and in Nrg1-mediated neurotrophic factor signaling