The molecular basis for ANE syndrome revealed by the large ribosomal subunit processome interactome

Elife. 2016 Apr 14:5:e16381. doi: 10.7554/eLife.16381.

Abstract

ANE syndrome is a ribosomopathy caused by a mutation in an RNA recognition motif of RBM28, a nucleolar protein conserved to yeast (Nop4). While patients with ANE syndrome have fewer mature ribosomes, it is unclear how this mutation disrupts ribosome assembly. Here we use yeast as a model system and show that the mutation confers growth and pre-rRNA processing defects. Recently, we found that Nop4 is a hub protein in the nucleolar large subunit (LSU) processome interactome. Here we demonstrate that the ANE syndrome mutation disrupts Nop4's hub function by abrogating several of Nop4's protein-protein interactions. Circular dichroism and NMR demonstrate that the ANE syndrome mutation in RRM3 of human RBM28 disrupts domain folding. We conclude that the ANE syndrome mutation generates defective protein folding which abrogates protein-protein interactions and causes faulty pre-LSU rRNA processing, thus revealing one aspect of the molecular basis of this human disease.

Keywords: ANE syndrome; Nop4; RNA recognition motif; S. cerevisiae; biophysics; chromosomes; genes; human; ribosome biogenesis; structural biology.

MeSH terms

  • Alopecia / physiopathology*
  • Circular Dichroism
  • Endocrine System Diseases / physiopathology*
  • Humans
  • Intellectual Disability / physiopathology*
  • Magnetic Resonance Spectroscopy
  • Models, Biological
  • Mutant Proteins / chemistry
  • Mutant Proteins / genetics
  • Mutant Proteins / metabolism*
  • Protein Binding
  • Protein Folding
  • Protein Interaction Maps
  • RNA Precursors / metabolism
  • RNA Processing, Post-Transcriptional
  • RNA-Binding Proteins / chemistry
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Ribonucleoproteins, Small Nucleolar / genetics
  • Ribonucleoproteins, Small Nucleolar / metabolism*
  • Ribosome Subunits, Large / metabolism*
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / growth & development
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae / physiology*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*

Substances

  • Mutant Proteins
  • NOP4 protein, S cerevisiae
  • RBM28 protein, human
  • RNA Precursors
  • RNA-Binding Proteins
  • Ribonucleoproteins, Small Nucleolar
  • Saccharomyces cerevisiae Proteins

Supplementary concepts

  • Alopecia, Neurologic Defects, and Endocrinopathy Syndrome