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Quach, K.

Publications and source records attributed to Quach, K..

2 recordsLinked to original sources

Coiled coil control of diverse EGFR functions

EGFR exhibits biased signaling, whereby growth factor or mutation-dependent changes in receptor conformation and/or dynamics elicit distinct intracellular outcomes. We report that many outcomes associated with activated EGFR are controlled by a two-state coiled coil switch located within the juxtamembrane segment (JM), an essential component of the cytosolic dimer interface. The position of this switch defines the path of endocytic trafficking and whether or not EGFR is degraded within lysosomes. JM coiled coil identity also predicts kinase-independent effects of oncogenic EGFR mutations and clinically relevant tyrosine kinase inhibitors (TKIs) that promote efficient, lysosome-based EGFR degradation. These findings provide a model for biased EGFR signaling, insights into kinase-independent activities of EGFR and clinically relevant TKIs, and identify new strategies for modulating protein lifetime.

biochemistry↗

Suppression of p53 response by targeting p53-Mediator binding with a stapled peptide

DNA-binding transcription factors (TFs) remain challenging to target with molecular probes. Many TFs function in part through interaction with Mediator; we sought to block p53 function by disrupting the p53-Mediator interaction. Through rational design and activity-based screening, we characterized a stapled peptide, with functional mimics of both p53 activation domains, that selectively inhibited p53- and Mediator-dependent transcription in vitro. This \"bivalent peptide\" also suppressed p53 transcriptional response in human cancer cells. Our strategy circumvents the TF and instead targets the TF-Mediator interface, with desired transcriptional outcomes. Different TFs target Mediator through different subunits, suggesting this strategy could be broadly applied.

molecular biology↗