Delineation of three functional domains of the transcriptional activator encoded by the c-myb protooncogene.
The c-myb protooncogene encodes a sequence-specific DNA-binding protein (c-Myb) that induces transcriptional activation or repression. We have identified three functional domains of the mouse c-Myb protein that are responsible for DNA binding, transcriptional activation, and negative regulation, respectively. In addition to the DNA-binding domain, which is located near the N terminus, an adjacent region (the transcriptional activation domain) containing about 80 amino acids was found to be essential for transcriptional activation. Deletion of a region spanning about 175 amino acids of the C-proximal portion increased transcriptional activation markedly, revealing that this domain normally represses activation. Differences between the transcriptional activation and repression functions of c-Myb and v-Myb are discussed in the light of these functional domains. Our results suggest that transcriptional activation may be involved in transformation by myb gene products.
Sakura
H
H
Laboratory of Molecular Genetics, Institute of Physical and Chemical Research (RIKEN), Ibaraki, Japan.
Kanei-Ishii
C
C
Nagase
T
T
Nakagoshi
H
H
Gonda
T J
TJ
Ishii
S
S
D000199:Actins / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D004268:DNA-Binding Proteins / Q000235:genetics*; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D020598:Proto-Oncogene Proteins c-myb; D011519:Proto-Oncogenes; D014158:Transcription, Genetic
D000199:Actins; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D020598:Proto-Oncogene Proteins c-myb