PMID- 10602419
OWN - NLM
STAT- MEDLINE
DCOM- 20000106
LR  - 20190915
IS  - 0887-6924 (Print)
IS  - 0887-6924 (Linking)
VI  - 13
IP  - 12
DP  - 1999 Dec
TI  - JEM-1, a novel nuclear co-factor: localisation and functional interaction with
      AP-1.
PG  - 1982-92
AB  - JEM-1 is a novel gene whose mRNA expression in acute promyelocytic leukemia (APL)
      is induced by retinoid treatments. The gene product, a 45 kDa basic nuclear
      factor containing a leucine repeat, was transiently expressed in HeLa or COS-7
      cells and immunocharacterized within the nuclei in fine punctuated structures
      which increase in size after cell transfection. Jem-1 was not expressed in the
      nucleoli. Experimental deletion of peptide domains of Jem-1 (JemDelta331-400 and 
      Jem DeltaL179-206) showed that its C-terminal sequence (Thr331 --> Leu400) is
      required for nuclear translocation, while the leucine repeat domain (Arg179 -->
      Glu206) has no influence on subcellular localization. The Jem-1 protein was not
      detected in the PML-containing nuclear bodies or in speckled structures
      containing the splicing factor SC-35. In contrast it was localized in the nucleus
      in structures containing activator protein-1 (AP-1). DNA mobility shift assays
      showed that the in vitro translated Jem protein interacts neither with the DNA
      binding site of AP-1, nor directly with in vitro co-translated c-Fos or/and c-Jun
      proteins bound to this specific sequence. Interestingly, Jem-1-1 increased
      substantially the transcriptional activity of c-Jun (three-fold) and more
      strongly that of ectopically co-expressed c-Fos and c-Jun (five- to six-fold), as
      measured by a CAT reporter gene driven by a heterologous promoter containing the 
      AP-1 binding site of the human collagenase gene. These synergistic effects were
      strongly Jem-1 dose-dependent. However, Jem-1 alone showed no activity on the
      collagenase promoter. A deletion of the leucine repeat of Jem-1 (Arg179 -->
      Glu206) did not diminish the enhancer capacity of Jem-1 on AP-1 activity. In
      contrast, the enhanced AP-1 activity was abrogated when Jem-1 was deleted of its 
      C-terminus (Thr331 --> Leu400). We conclude that the 45 kDa nuclear product of
      the JEM-1 gene has features of a novel transcription cofactor, which is enhancing
      AP-1 activity without directly interacting with c-Jun or c-Fos proteins. Possible
      implications of these findings for APL cell maturation are discussed.
FAU - Tong, J H
AU  - Tong JH
AD  - Institut National de la Sante et de la Recherche Medicale, INSERM-U496, Institut 
      Universitaire d'Hematologie, Centre G Hayem, Hopital Saint-Louis, F-75475 Paris, 
      France.
FAU - Duprez, E
AU  - Duprez E
FAU - Lanotte, M
AU  - Lanotte M
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Leukemia
JT  - Leukemia
JID - 8704895
RN  - 0 (BLZF1 protein, human)
RN  - 0 (Basic Helix-Loop-Helix Leucine Zipper Transcription Factors)
RN  - 0 (Nuclear Proteins)
RN  - 0 (Transcription Factor AP-1)
RN  - 0 (Transcription Factors)
SB  - IM
MH  - Animals
MH  - Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
MH  - COS Cells
MH  - Cell Nucleus/*chemistry
MH  - HeLa Cells
MH  - Humans
MH  - Nuclear Proteins/*analysis/genetics/physiology
MH  - Transcription Factor AP-1/*physiology
MH  - Transcription Factors/*analysis/genetics/physiology
EDAT- 1999/12/22 00:00
MHDA- 1999/12/22 00:01
CRDT- 1999/12/22 00:00
PHST- 1999/12/22 00:00 [pubmed]
PHST- 1999/12/22 00:01 [medline]
PHST- 1999/12/22 00:00 [entrez]
AID - 10.1038/sj.leu.2401560 [doi]
PST - ppublish
SO  - Leukemia. 1999 Dec;13(12):1982-92. doi: 10.1038/sj.leu.2401560.