Functional serum response elements upstream of the growth factor-inducible gene zif268.
The zif268 gene, which encodes a protein with three typical zinc finger sequences, is induced in mouse 3T3 cells by serum, phorbol 12-myristate 13-acetate platelet-derived growth factor, and fibroblast growth factor. The induction is coordinate with that of c-fos. The 5'-flanking region of zif268 contains sequences that resemble known regulatory elements, including four CC(A or T)6GG sequences similar to the core serum response elements (SREs) found upstream of c-fos and actin genes. To determine whether the zif268 SRE-like elements mediate induction, CAT (chloramphenicol acetyltransferase) plasmids with different lengths of zif268 upstream sequences were tested for inducibility in 3T3 cells by serum, platelet-derived growth factor, or phorbol 12-myristate 13-acetate. In addition, double-stranded oligonucleotides corresponding to each of the four zif268 putative SREs were tested individually for responsiveness when placed upstream of a thymidine kinase gene promoter. Each of the four SREs conferred inducibility by the agents tested, and multiple SREs resulted in greater inducibility than did a single element. Each of the zif268 SREs also competed with the c-fos SRE for binding by serum response factor present in HeLa cell nuclear extract. We conclude that the zif268 SRE-like sequences are functional and probably account for the coordinate induction of zif268 and c-fos.
Christy
B
B
Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
Nathans
D
D
D000818:Animals; D001483:Base Sequence; D001667:Binding, Competitive; D001769:Blood; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000378:metabolism; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005346:Fibroblast Growth Factors / Q000494:pharmacology; D005786:Gene Expression Regulation; D005796:Genes; D008667:Metalloproteins / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D010957:Plasmids; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013937:Thymidine Kinase / Q000235:genetics; D014162:Transfection; D015032:Zinc
D004268:DNA-Binding Proteins; D008667:Metalloproteins; D010982:Platelet-Derived Growth Factor; D005346:Fibroblast Growth Factors; D015500:Chloramphenicol O-Acetyltransferase; D013937:Thymidine Kinase; D015032:Zinc; D013755:Tetradecanoylphorbol Acetate