The BRCT domain of mammalian Pes1 is crucial for nucleolar localization and rRNA processing

Nucleic Acids Res. 2007;35(3):789-800. doi: 10.1093/nar/gkl1058. Epub 2006 Dec 22.

Abstract

The nucleolar protein Pes1 interacts with Bop1 and WDR12 in a stable complex (PeBoW-complex) and its expression is tightly associated with cell proliferation. The yeast homologue Nop7p (Yph1p) functions in both, rRNA processing and cell cycle progression. The presence of a BRCT-domain (BRCA1 C-terminal) within Pes1 is quite unique for an rRNA processing factor, as this domain is normally found in factors involved in DNA-damage or repair pathways. Thus, the function of the BRCT-domain in Pes1 remains elusive. We established a conditional siRNA-based knock-down-knock-in system and analysed a panel of Pes1 truncation mutants for their functionality in ribosome synthesis in the absence of endogenous Pes1. Deletion of the BRCT-domain or single point mutations of highly conserved residues caused diffuse nucleoplasmic distribution and failure to replace endogenous Pes1 in rRNA processing. Further, the BRCT-mutants of Pes1 were less stable and not incorporated into the PeBoW-complex. Hence, the integrity of the BRCT-domain of Pes1 is crucial for nucleolar localization and its function in rRNA processing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Cell Nucleolus / chemistry*
  • Humans
  • Nuclear Proteins / analysis
  • Nuclear Proteins / chemistry*
  • Nuclear Proteins / metabolism*
  • Point Mutation
  • Protein Structure, Tertiary / genetics
  • Proteins / analysis
  • Proteins / chemistry*
  • Proteins / metabolism*
  • RNA Interference
  • RNA Processing, Post-Transcriptional*
  • RNA, Ribosomal / metabolism*
  • RNA-Binding Proteins
  • Sequence Deletion

Substances

  • Nuclear Proteins
  • PES1 protein, human
  • Proteins
  • RNA, Ribosomal
  • RNA-Binding Proteins