Cloning and characterization of LUN, a novel ring finger protein that is highly expressed in lung and specifically binds to a palindromic sequence

J Biol Chem. 2001 Apr 27;276(17):14004-13. doi: 10.1074/jbc.M010262200. Epub 2001 Jan 25.

Abstract

We isolated cDNAs encoding a novel RING finger protein (LUN), the mRNAs of which were expressed at high levels in the lung. In situ hybridization revealed that LUN mRNAs were expressed in the alveolar epithelium of the lung. The LUN gene locus was assigned to chromosome 9p21, which contains candidate tumor suppressor genes associated with loss of heterozygosity in more than 86% of small cell lung cancers. We clarified that LUN is localized to the nucleus and reveals Zn(2+)-dependent DNA binding activity. The region from amino acids 51 to 374 of LUN is responsible for DNA binding. Furthermore, we identified a novel palindromic binding consensus (5'-TCCCAGCACTTTGGGA-3') for the LUN binding. Interestingly, this LUN binding palindromic sequence is found in the upstream transcriptional regulatory region of the E-cadherin gene and two intervening regions of the talin gene. Our results suggested that LUN might be an important trans-acting transcriptional regulator for lung cancer-associated genes including E-cadherin and talin genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Binding Sites
  • Blotting, Northern
  • Cadherins / metabolism
  • Carrier Proteins*
  • Cations
  • Cell Nucleus / metabolism
  • Chromosome Mapping
  • Chromosomes, Human, Pair 9
  • Cloning, Molecular
  • DNA / metabolism
  • DNA, Complementary / metabolism
  • DNA-Binding Proteins / chemistry*
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism
  • Epithelium / metabolism
  • Forkhead Transcription Factors
  • Gene Library
  • Glutathione Transferase / metabolism
  • HeLa Cells
  • Humans
  • In Situ Hybridization
  • In Situ Hybridization, Fluorescence
  • Loss of Heterozygosity
  • Lung / metabolism*
  • Molecular Sequence Data
  • Neoplasm Proteins*
  • Nuclear Proteins*
  • Protein Binding
  • Protein Structure, Tertiary
  • Pulmonary Alveoli / metabolism
  • RNA, Messenger / metabolism
  • Recombinant Fusion Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid
  • Tissue Distribution
  • Trans-Activators / biosynthesis
  • Trans-Activators / chemistry*
  • Trans-Activators / genetics*
  • Transcription Factors*
  • Transcription, Genetic
  • Transfection
  • Ubiquitin-Protein Ligases
  • Zinc / metabolism

Substances

  • Cadherins
  • Carrier Proteins
  • Cations
  • DNA, Complementary
  • DNA-Binding Proteins
  • FOXF2 protein, human
  • Forkhead Transcription Factors
  • LUN protein, vertebrate
  • Neoplasm Proteins
  • Nuclear Proteins
  • RNA, Messenger
  • Recombinant Fusion Proteins
  • Trans-Activators
  • Transcription Factors
  • DNA
  • TOPORS protein, human
  • Ubiquitin-Protein Ligases
  • Glutathione Transferase
  • Zinc

Associated data

  • GENBANK/AB045732
  • GENBANK/AB045733