Negative regulation of the mouse aldolase A gene. A cell cycle-dependent DNA binding activity functions as a silencer of gene transcription.
The expression of aldolase A L-type mRNA is increased in growth-arrested mouse NIH3T3 cells and remarkably down-regulated in actively proliferating cells. Treatment of proliferating cells with cycloheximide abolished the down-regulation of L-type mRNA expression, thus indicating that a protein factor acts as repressor in proliferating cells. Transient transfection experiments in NIH3T3 cells showed that a negative regulatory cis-element (NRE) is involved in the modulation of the transcriptional activity of the distal L promoter. The repressor, which is a protein of approximately 97 kDa, binds the murine aldolase A NRE, revealing a much more intense DNA-protein complex in proliferating NIH3T3 cells than in serum-deprived cells. Mutations in the negative regulatory cis-element showed that the GA-rich motif is required for protein binding and silencer function. We conclude that the expression of L-type mRNA is modulated by the interaction between a cell cycle-dependent DNA-binding protein and the murine aldolase A NRE.
Lupo
A
A
Dipartimento di Biochimica e Biotecnologie Mediche, Facoltà di Medicina e Chirurgia, Italy.
Costanzo
P
P
Medugno
L
L
Romeo
I
I
Salvatore
F
F
Izzo
P
P
D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002453:Cell Cycle; D002455:Cell Division; D003513:Cycloheximide / Q000494:pharmacology; D004247:DNA / Q000378:metabolism*; D003609:Dactinomycin / Q000494:pharmacology; D005634:Fructose-Bisphosphate Aldolase / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism; D014158:Transcription, Genetic
D019384:Nucleic Acid Synthesis Inhibitors; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D003609:Dactinomycin; D004247:DNA; D003513:Cycloheximide; D012260:Ribonucleases; D005634:Fructose-Bisphosphate Aldolase