1JZU

Cell transformation by the myc oncogene activates expression of a lipocalin: analysis of the gene (Q83) and solution structure of its protein product


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the least restraint violations,structures with the lowest energy 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Cell Transformation by the v-myc Oncogene Abrogates c-Myc/Max-mediated Suppression of a C/EBPbeta-dependent Lipocalin Gene.

Hartl, M.Matt, T.Schueler, W.Siemeister, G.Kontaxis, G.Kloiber, K.Konrat, R.Bister, K.

(2003) J.Mol.Biol. 333: 33-46


  • PubMed Abstract: 
  • Using differential hybridization techniques, a cDNA clone (Q83) was isolated that corresponds to a highly abundant mRNA in quail embryo fibroblasts transformed by the v-myc oncogene. The deduced 178 amino acid protein product of Q83 contains an N-ter ...

    Using differential hybridization techniques, a cDNA clone (Q83) was isolated that corresponds to a highly abundant mRNA in quail embryo fibroblasts transformed by the v-myc oncogene. The deduced 178 amino acid protein product of Q83 contains an N-terminal signal sequence and a lipocalin sequence motif, the hallmark of a family of secretory proteins binding and transporting small hydrophobic molecules of diverse biological function, including retinoids and steroids. The quail Q83 protein displays 87% sequence identity with a developmentally regulated chicken protein, termed p20K or Ch21. Cell transformation specifically by v-myc, but not by other oncogenic agents, induces high-level expression of Q83 mRNA and of the Q83 protein. Nucleotide sequence analysis and transcriptional mapping revealed that the Q83 gene encompasses seven exons with the coding region confined to exons 1 through 6. The promoter region contains consensus binding sites for the transcriptional regulators Myc and C/EBP beta. Transcriptional activation of Q83 is principally dependent on C/EBP beta, but is blocked in normal cells by the endogenous c-Myc/Max/Mad transcription factor network. In v-myc-transformed cells, high-level expression of the v-Myc protein and formation of highly stable v-Myc/Max heterodimers leads to abrogation of Q83 gene suppression and activation by C/EBP beta. A 157 amino acid residue recombinant protein representing the secreted form of Q83 was used for structure determination by nuclear magnetic resonance spectroscopy. Q83 folds into a single globular domain of the lipocalin-type. The central part consists of an eight-stranded up-and-down beta-barrel core flanked by an N-terminal 3(10)-like helix and a C-terminal alpha-helix. The orientation of the C-terminal alpha-helix is partially determined by a disulfide bridge between Cys59 and Cys152. The three-dimensional structure determination of the Q83 protein will facilitate the identification of its authentic ligand and the assessment of its biological function, including the putative role in myc-induced cell transformation.


    Related Citations: 
    • Sequence-Specific Resonance Assignments of Q83, a Lipocalin Highly Expressed in v-myc-Transformed Avian Fibroblasts
      Kontaxis, G.,Matt, T.,Schueler, W.,Kraeutler, B.,Bister, K.,Konrat, R.
      (2000) J.Biomol.NMR 17: 177


    Organizational Affiliation

    Institute of Biochemistry, University of Innsbruck, A-6020 Innsbruck, Austria.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
lipocalin Q83
A
157Coturnix japonicaMutation(s): 1 
Find proteins for Q9I9P7 (Coturnix japonica)
Go to UniProtKB:  Q9I9P7
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the least restraint violations,structures with the lowest energy 
  • Olderado: 1JZU Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-07-15
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance