Regulation of the murine NMDA-receptor-subunit NR2C promoter by Sp1 and fushi tarazu factor1 (FTZ-F1) homologues.
We have cloned the 5'-region of the murine N-methyl-d-aspartate (NMDA) receptor channel subunit NR2C (GluRepsilon3) gene and characterized the cis- and trans-activating regulatory elements responsible for its tissue specific activity. By using a native epsilon3-promoter/lacZ-construct & various 5'-deletion constructs, we compared beta-galactosidase expression in non-neuronal NIH3T3 cells and in neuronal epsilon3-gene-expressing HT-4 cells and show that large parts of the epsilon3 promoter are responsible for the repression of the epsilon3 gene in non-neuronal cells. Deletion of exon 1 sequences led to an enhancement of epsilon3 transcription, suggesting a role of the 5'-untranslated region in epsilon3 gene regulation. Sequence analysis of the promoter region revealed potential binding sites for the transcription factor Sp1, the murine fushi tarazu factor1 (FTZ-F1) homologues, embryonic LTR binding proteins (ELP1,2,3) and steroidogenic factor (SF-1), as well as for the chicken ovalbumin upstream promoter transcription-factor (COUP-TF). Electrophoretic mobility shift assays confirmed specific binding of Sp1, SF-1 and COUP-TFI. Whereas point mutation studies indicate that, in neuronal HT-4 cells, Sp1 is apparently not critically involved in basal epsilon3 gene transcription, SF1 is a positive regulator. This was evident from a selective enhancement of epsilon3-promoter-driven reporter gene expression upon cotransfection of an SF1-expression vector, which was reverted by deletion and point mutation of the SF1 binding site.
Pieri
I
I
Institute of Cell Biology and Immunology, University of Stuttgart, Germany.
Klein
M
M
Bayertz
C
C
Gerspach
J
J
van der Ploeg
A
A
Pfizenmaier
K
K
Eisel
U
U
D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence / Q000235:genetics; D002460:Cell Line; D046508:Culture Techniques; D004268:DNA-Binding Proteins / Q000502:physiology*; D051717:Fushi Tarazu Transcription Factors; D015870:Gene Expression / Q000502:physiology; D018398:Homeodomain Proteins; D007536:Isomerism; D007763:Lac Operon / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics / Q000502:physiology*; D018160:Receptors, Cytoplasmic and Nuclear; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics* / Q000378:metabolism; D016329:Sp1 Transcription Factor / Q000502:physiology*; D054339:Steroidogenic Factor 1; D014157:Transcription Factors / Q000378:metabolism / Q000502:physiology*
D004268:DNA-Binding Proteins; D051717:Fushi Tarazu Transcription Factors; D018398:Homeodomain Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D016194:Receptors, N-Methyl-D-Aspartate; D016329:Sp1 Transcription Factor; D054339:Steroidogenic Factor 1; D014157:Transcription Factors