Zinc finger protein overexpressed in colon carcinoma interacts with the telomeric protein hRap1

J Cell Biochem. 2005 Jul 1;95(4):763-8. doi: 10.1002/jcb.20487.

Abstract

The OZF (ZNF146) protein is a 33 kDa Kruppel protein, composed solely of 10 zinc finger motifs. It is overexpressed in the majority of pancreatic cancers and in more than 80% of colorectal cancers. We found an interaction between OZF and the telomeric hRap1 protein with a yeast two-hybrid screen. hRap1 (TERF2IP) is an ortholog of the yeast telomeric protein, scRap1 originally identified as a regulator of telomere length. In HeLa cells, it interacts with TRF2, a telomere repeat binding factor whose inactivation causes a dysregulation of telomere length and structure. Immunoprecipitation with anti-hRap1 antibodies in conditions that allow the purification of proteins associated with hRap1, demonstrated that OZF binds to hRap1 in HeLa cells. Using deletion mutants, we mapped the interacting domain of each protein. The three zinc fingers at the C-terminus of OZF interact with a region of hRap1 located downstream of the coil domain. It involves a stretch of at least 25 amino acids at the C-terminus of hRap1 that interact with TRF2. This suggests that OZF overexpression in tumours may alter the balance between hRap1 and other telomeric proteins and therefore that OZF function may be linked to telomere regulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Colonic Neoplasms / genetics
  • Colonic Neoplasms / metabolism*
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Gene Expression Regulation, Neoplastic
  • HeLa Cells
  • Humans
  • Immunoprecipitation
  • Kruppel-Like Transcription Factors
  • Protein Binding
  • RNA-Binding Proteins / chemistry
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Shelterin Complex
  • Telomere-Binding Proteins / genetics
  • Telomere-Binding Proteins / metabolism*
  • Two-Hybrid System Techniques
  • Zinc Fingers*

Substances

  • DNA-Binding Proteins
  • Kruppel-Like Transcription Factors
  • RNA-Binding Proteins
  • Shelterin Complex
  • TERF2IP protein, human
  • Telomere-Binding Proteins
  • ZNF146 protein, human