JEM-1, a novel gene encoding a leucine-zipper nuclear factor upregulated during retinoid-induced maturation of NB4 promyelocytic leukaemia

Oncogene. 1997 Apr 3;14(13):1563-70. doi: 10.1038/sj.onc.1200995.


Retinoid-induced proliferation causing hyperleukocytosis is a severe complication of retinoid therapy in t(15;17) acute promyelocytic leukaemia. The molecular basis of this phenomenon is unknown. It is possible that the transiently enhanced cell proliferation results from RA-induction of growth regulatory genes. Using Differential Display of cDNAs from NB4 cells we have identified Jem, a novel gene transcript which is upregulated by retinoids during the early proliferative response in maturating cells but not in resistant cells. A 2.7 kb cDNA was cloned and sequenced. The open reading frame contains a 400 amino acid sequence corresponding to a novel 45 kDa basic protein (pI 8.9). The JEM DNA sequence is detected by FISH on human chromosome 1 at q24. The Jem peptide sequence shows a 'leucine-zipper' dimerisation motif with limited homology to Fos/Jun and ATF/CREB proteins and several putative phosphorylation sites. An atypical basic region may correspond to an unknown DNA-binding domain. The C-terminal end of Jem spans a long stretch featuring a PEST motif. After transfection into COS cells, the Jem protein shows a ponctuated nuclear localisation. We hypothesise that this novel nuclear factor may act as a transcription factor, or a coregulator, involved in either cell growth control and/or maturation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • COS Cells
  • Cell Nucleus / chemistry
  • Chromosome Mapping
  • Chromosomes, Human, Pair 1
  • Cloning, Molecular
  • DNA, Complementary
  • Dimerization
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • In Situ Hybridization, Fluorescence
  • Leucine Zippers*
  • Leukemia, Promyelocytic, Acute / genetics*
  • Leukemia, Promyelocytic, Acute / metabolism
  • Molecular Sequence Data
  • Nuclear Proteins / analysis
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / genetics*
  • Phosphorylation
  • Protein Biosynthesis
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Neoplasm / genetics
  • RNA, Neoplasm / metabolism
  • Transcription Factors / analysis
  • Transcription Factors / chemistry
  • Transcription Factors / genetics*
  • Transcription, Genetic
  • Transfection
  • Tretinoin / pharmacology*


  • BLZF1 protein, human
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • DNA, Complementary
  • Nuclear Proteins
  • RNA, Messenger
  • RNA, Neoplasm
  • Transcription Factors
  • Tretinoin

Associated data

  • GENBANK/U79751