Pathogenic NAP57 Mutations Decrease Ribonucleoprotein Assembly in Dyskeratosis Congenita

Hum Mol Genet. 2009 Dec 1;18(23):4546-51. doi: 10.1093/hmg/ddp416. Epub 2009 Sep 4.

Abstract

X-linked dyskeratosis congenita (DC) is a rare bone marrow failure syndrome caused by mostly missense mutations in the pseudouridine synthase NAP57 (dyskerin/Cbf5). As part of H/ACA ribonucleoproteins (RNPs), NAP57 is important for the biogenesis of ribosomes, spliceosomal small nuclear RNPs, microRNAs and the telomerase RNP. DC mutations concentrate in the N- and C-termini of NAP57 but not in its central catalytic domain raising questions as to their impact. We demonstrate that the N- and C-termini together form the binding surface for the H/ACA RNP assembly factor SHQ1 and that DC mutations modulate the interaction between the two proteins. Pinpointing impaired interaction between NAP57 and SHQ1 as a potential molecular basis for X-linked DC has implications for therapeutic approaches, e.g. by targeting the NAP57-SHQ1 interface with small molecules.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Motifs
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Dyskeratosis Congenita / genetics*
  • Dyskeratosis Congenita / metabolism*
  • Dyskeratosis Congenita / pathology
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Molecular Conformation
  • Mutation*
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / metabolism
  • Protein Binding
  • Ribonucleoproteins / genetics
  • Ribonucleoproteins / metabolism*

Substances

  • Carrier Proteins
  • Intracellular Signaling Peptides and Proteins
  • NAP57
  • Nuclear Proteins
  • Ribonucleoproteins
  • SHQ1 protein, human