THE MACROPHAGE AND B-CELL SPECIFIC TRANSCRIPTION FACTOR PU.1 IS RELATED TO THE ETS ONCOGENE

We have isolated a cDNA clone, PU.1, that codes for a new tissue-specific DNA binding protein. Analysis of the binding site by methylation interference and DNA-ase I protection revealed that the PU.1 protein recognized a purine-rich sequence, 5′-GAGGAA-3′ (PU box). The PU.1 protein was shown to be a transcriptional activator that is expressed in macrophages and B cells. cDNA constructions used to generate proteins lacking portions of either the amino- or carboxy-terminal ends of the PU.1 protein placed the DNA binding domain in the highly basic carboxy-terminal domain of the protein. The amino acid sequence in the binding domain of PU.1 has considerable identity with proteins belonging to the ets oncogene family. © 1990.