Transcriptional activity and constitutive nuclear localization of the ETS protein Elf-1. 
Elf-1 is a lymphoid-specific transcription factor that belongs to the ETS protein family. It can bind to DNA target sequences within a variety of cytokine genes. We demonstrate that Elf-1 is constitutively localized in the nucleus which is dependent on the presence of amino acids 86-265. Analysis of Gal4-Elf-1 fusion proteins revealed that the N-terminal 86 amino acids of Elf-1 contain a transcriptional activation domain, the activity of which is attenuated by an internal repression domain. Furthermore, Elf-1 interacts specifically with the E74 target sequence and can stimulate transcription driven by the E74 site independent of mitogenic signaling. Thus, Elf-1 is able to stimulate gene transcription which may be required for the development and activity of lymphocytes.