Heterodimer formation between CREB and JUN proteins.
DNA binding protein families have been identified that contain a leucine zipper dimerization motif preceded by a conserved, highly basic domain involved in direct specific interaction with DNA. Members of two of these families, the Jun and Fos related proteins, have been shown to directly interact and form heterodimeric complexes. A third such family known as the CREB or ATF proteins, bind to a sequence element present in promoters from a number of viral and cellular genes; this element can confer cAMP-inducibility and E1A-inducibility of transcription. In this report we show that one member of the CREB family can efficiently form a heterodimeric complex with the cJun protein. The DNA binding specificity of the heterodimer was indistinguishable from CREB alone. Transfection studies in undifferentiated F9 cells suggest that the CREB/cJun heterodimer can form in vivo, but that the complex does not activate transcription. The heterodimer formation between CREB and Jun proteins is highly specific; only one of the two CREB proteins would heterodimerize with cJun and it would not form dimers with JunB or cFos. The interaction of members of these two families of proteins increases the repertoire of possible regulatory complexes that could play an important role in the regulation of transcription of specific cellular genes.
Benbrook
D M
DM
Gene Regulation Laboratory, Imperial Cancer Research Fund, Lincoln's Inn Fields, London, UK.
Jones
N C
NC
D001483:Base Sequence; D002460:Cell Line; D017362:Cyclic AMP Response Element-Binding Protein; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015723:Gene Library; D005822:Genetic Vectors; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun; D011519:Proto-Oncogenes; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
D017362:Cyclic AMP Response Element-Binding Protein; D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D015345:Oligonucleotide Probes; D016755:Proto-Oncogene Proteins c-jun; D014157:Transcription Factors; D004247:DNA; D011505:Protein-Tyrosine Kinases