A gene encoding a protein with zinc fingers is activated during G0/G1 transition in cultured cells.

Zinc fingers are DNA‐binding domains present in several eukaryotic regulatory proteins. We have identified a mouse gene, Krox‐20, encoding a protein with three zinc fingers and whose expression is activated during G0/G1 transition in cultured cells. Serum stimulation of quiescent cells leads to rapid and transient accumulation of Krox‐20 mRNA, with kinetics similar to those of the c‐fos proto‐oncogene. The induction does not require de‐novo protein synthesis. In the mouse, Krox‐20 is expressed at low levels in tissues which contain rapidly dividing cells. These properties suggest that Krox‐20 encodes a transcription control factor, possibly involved in the modulation of cell proliferation.