Definition: Promoter-specific RNA polymerase II transcription factor that binds to the GC box, one of the upstream promoter elements, in mammalian cells. The binding of Sp1 is necessary for the initiation of transcription in the promoters of a variety of cellular and viral GENES.
/drug eff /ultrastruct permitted; in titles & translations use SP1 (the figure one), not SPl (the letter l)
Other names Transcription Factor, Sp1; Specificity Protein 1 Transcription Factor