Systematic identification of pathological lamin A interactors

Mol Biol Cell. 2014 May;25(9):1493-510. doi: 10.1091/mbc.E14-02-0733. Epub 2014 Mar 12.

Abstract

Laminopathies are a collection of phenotypically diverse diseases that include muscular dystrophies, cardiomyopathies, lipodystrophies, and premature aging syndromes. Laminopathies are caused by >300 distinct mutations in the LMNA gene, which encodes the nuclear intermediate filament proteins lamin A and C, two major architectural elements of the mammalian cell nucleus. The genotype-phenotype relationship and the basis for the pronounced tissue specificity of laminopathies are poorly understood. Here we seek to identify on a global scale lamin A-binding partners whose interaction is affected by disease-relevant LMNA mutations. In a screen of a human genome-wide ORFeome library, we identified and validated 337 lamin A-binding proteins. Testing them against 89 known lamin A disease mutations identified 50 disease-associated interactors. Association of progerin, the lamin A isoform responsible for the premature aging disorder Hutchinson-Gilford progeria syndrome, with its partners was largely mediated by farnesylation. Mapping of the interaction sites on lamin A identified the immunoglobulin G (IgG)-like domain as an interaction hotspot and demonstrated that lamin A variants, which destabilize the Ig-like domain, affect protein-protein interactions more globally than mutations of surface residues. Analysis of a set of LMNA mutations in a single residue, which result in three phenotypically distinct diseases, identified disease-specific interactors. The results represent a systematic map of disease-relevant lamin A interactors and suggest loss of tissue-specific lamin A interactions as a mechanism for the tissue-specific appearance of laminopathic phenotypes.

Publication types

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

MeSH terms

  • Cell Line, Tumor
  • Gene Ontology
  • Humans
  • Lamin Type A / chemistry
  • Lamin Type A / genetics
  • Lamin Type A / metabolism*
  • Mutation, Missense
  • Prenylation
  • Protein Binding
  • Protein Interaction Mapping
  • Protein Processing, Post-Translational
  • Proteostasis Deficiencies / genetics
  • Two-Hybrid System Techniques

Substances

  • LMNA protein, human
  • Lamin Type A