CROC-1 encodes a protein which mediates transcriptional activation of the human FOS promoter

Gene. 1997 Aug 22;195(2):141-9. doi: 10.1016/s0378-1119(97)00097-8.


The cloning of signal transducing molecules capable of activating the human FOS proto-oncogene promoter was achieved by co-transfecting a modified human FOS promoter-driven polyomavirus large T antigen gene (P(f)LAG-8) with a human brain cDNA library, incorporated into a replication-competent mammalian retroviral expression vector whose replication occurs in the presence of T antigen. In murine cells, transcriptional activation of the P(f)LAG-8 promoter by a biologically active, cDNA-encoded signalling molecule resulted in plasmid replication. Replicated plasmids, following selective cleavage of unreplicated plasmids by Dpn1, were recovered by transformation into competent bacteria. Successive P(f)LAG-8/cDNA library co-transfections, using library plasmids resulting from prior transfections, ultimately resulted in the identification of individual plasmids capable of transcriptionally activating the FOS promoter. DNA sequencing revealed the first plasmid, denoted CROC-1, to contain a 1.8-kb cDNA encoding a 16.5-kDa nuclear protein possessing a bipartite structure comprised an amino-terminal acidic domain and a carboxy-terminal basic domain, and displaying partial homology to the HMG domain of the TAF(II)250 transcription cofactor. Co-transfection of CROC-1 with various FOS/CAT reporter genes revealed that the human FOS promoter region spanning -56 to - 105, encompassing two identical 8-bp DR enhancer sequences, was necessary for CROC-1-mediated transcriptional activation. Results suggest that CROC-1 participates in intracellular signalling pathways involved in induction of the human FOS promoter.

MeSH terms

  • 3T3 Cells
  • Amino Acid Sequence
  • Animals
  • Antigens, Viral, Tumor / genetics
  • Base Sequence
  • Cells, Cultured
  • Gene Library
  • Genes, Reporter
  • Genes, fos
  • Genetic Vectors
  • Humans
  • Mice
  • Molecular Sequence Data
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / metabolism
  • Plasmids / genetics*
  • Polyomavirus / genetics
  • Promoter Regions, Genetic
  • Proto-Oncogene Proteins c-fos / genetics*
  • Rats
  • Repetitive Sequences, Nucleic Acid
  • Sequence Analysis, DNA
  • Signal Transduction / genetics*
  • Trans-Activators / genetics*
  • Trans-Activators / metabolism
  • Transcription Factors*
  • Transcriptional Activation*
  • Transformation, Genetic
  • Ubiquitin-Conjugating Enzymes*


  • Antigens, Viral, Tumor
  • Nuclear Proteins
  • Proto-Oncogene Proteins c-fos
  • Trans-Activators
  • Transcription Factors
  • UBE2V1 protein, human
  • Ubiquitin-Conjugating Enzymes

Associated data

  • GENBANK/U39360
  • GENBANK/U39361