Mammalian Krüppel-like transcription factors: more than just a pretty finger.

The transcription factor SP1 contains three Krüppel-like zinc fingers. Recently, several related proteins, including erythroid, lung and gut-enriched Krüppel-like factors, have been identified. Together with SP1, these proteins form a sizeable family of transcription factors that share homology in their zinc-finger domains but differ elsewhere. Analysis of these differences is illuminating specific mechanisms by which transcription is regulated.