Activation of transcription by PU.1 requires both acidic and glutamine domains.
The B-lymphocyte- and macrophage-specific transcription factor PU.1 is a member of the ets family of proteins. To understand how PU.1 functions as a transcription factor, we initiated a series of experiments to define its activation domain. Using deletion analysis, we showed that the activation domain of PU.1 is located in the amino-terminal half of the protein. Within this region, we identified three acidic subdomains and one glutamine-rich subdomain. The deletion of any of these subdomains resulted in a significant loss in the ability of PU.1 to transactivate in cotransfection studies. Amino acid substitution analysis showed that the activation of transcription by PU.1 requires acidic residues between amino acids 7 and 74 and a group of glutamine residues between amino acids 75 and 84. These data show that PU.1 contains two types of known activation domains and that both are required for maximal transactivation.
Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis 46202, USA.
M J
MJ
Klemsz
R A
RA
Maki
D000143:Acids / Q000737:chemistry; D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005973:Glutamine / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010449:Peptide Mapping; D015682:Retroviridae Proteins, Oncogenic; D017384:Sequence Deletion; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D014162:Transfection
D000143:Acids; D004268:DNA-Binding Proteins; D015682:Retroviridae Proteins, Oncogenic; D014157:Transcription Factors; C062022:v-Spi-1 protein, Friend spleen focus-forming virus; D005973:Glutamine