Mutations in disordered regions cause disease by creating dileucine motifs - peptide-protein interaction screen

ABSTRACT: Many disease-causing missense mutations affect intrinsically disordered regions (IDRs) of proteins. Since these mutations do not affect protein structure, the molecular mechanism of their pathogenicity is enigmatic. Here, we employ a peptide-based proteomic screen to investigate the impact of mutations in IDRs on protein-protein interactions. We find that mutations in disordered cytosolic regions of three transmembrane proteins (GLUT1, ITPR1 and CACNA1H) lead to an increased binding of clathrin. In all three cases, the mutation creates a dileucine motif known to mediate clathrin-dependent trafficking. Follow-up experiments on full length GLUT1 (SLC2A1), the glucose transporter causative of GLUT1 deficiency syndrome, revealed that the mutated protein mislocalizes to intracellular compartments in a model cell line and in patient-derived induced pluripotent stem cells. Mutant GLUT1 interacts with adaptor proteins (APs) in vitro, and knocking-down AP-2 reverts the cellular mislocalization. A systematic analysis of other known disease-causing variants revealed a significant and specific overrepresentation of gained dileucine motifs in structurally disordered cytosolic domains of transmembrane proteins. Thus, several mutations in disordered regions appear to cause “dileucineopathies”.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Cell Culture

SUBMITTER: Katrina Meyer  

LAB HEAD: Matthias Selbach

PROVIDER: PXD010027 | Pride | 2018-09-13

REPOSITORIES: Pride