De novo TBR1 mutations in sporadic autism disrupt protein functions

Nat Commun. 2014 Sep 18:5:4954. doi: 10.1038/ncomms5954.

Abstract

Next-generation sequencing recently revealed that recurrent disruptive mutations in a few genes may account for 1% of sporadic autism cases. Coupling these novel genetic data to empirical assays of protein function can illuminate crucial molecular networks. Here we demonstrate the power of the approach, performing the first functional analyses of TBR1 variants identified in sporadic autism. De novo truncating and missense mutations disrupt multiple aspects of TBR1 function, including subcellular localization, interactions with co-regulators and transcriptional repression. Missense mutations inherited from unaffected parents did not disturb function in our assays. We show that TBR1 homodimerizes, that it interacts with FOXP2, a transcription factor implicated in speech/language disorders, and that this interaction is disrupted by pathogenic mutations affecting either protein. These findings support the hypothesis that de novo mutations in sporadic autism have severe functional consequences. Moreover, they uncover neurogenetic mechanisms that bridge different neurodevelopmental disorders involving language deficits.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Autism Spectrum Disorder / genetics*
  • Cell Line, Tumor
  • Child
  • Child, Preschool
  • Dimerization
  • Female
  • Forkhead Transcription Factors / metabolism
  • HEK293 Cells
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Language Disorders / genetics
  • Male
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Mutation*
  • Mutation, Missense
  • Protein Interaction Mapping
  • Sequence Homology, Amino Acid
  • T-Box Domain Proteins / genetics*
  • Two-Hybrid System Techniques

Substances

  • FOXP2 protein, human
  • Forkhead Transcription Factors
  • T-Box Domain Proteins
  • TBR1 protein, human