~,bstraet Zinc-finger proteins are involved in several cellular processes. Some of these proteins are implicated in the primary cellular response in regenerating liver and mitogen-stimulated cells. Using a rat cDNA brain library, we have isolated a clone designated NOR-2, encoding a protein containing two zinc-finger motifs and whose expression is highly induced during G0/GI transition. We analysed the expression of NOR-2 mRNAs during early growth in regenerating liver and in both insulin-stimulated H4-11 cells and pheochromocytoma-derived cell line PCI2 treated by NGF. In these systems, there is an early, rapid and transient accumulation of NOR-2 mRNAs. The induction of NOR-2 mRNAs does not require de novo protein synthesis, since it is not prevented by cycloheximide treatment. Mobility shift assays show that NOR-2 protein binds to NBRE, a target sequence for r-NGFI-B family. Structurally, NOR-2 is closely related to the recently identified NOR-I factor. Therefore, like NOR-I, NOR-2 belongs to the r-NGFI-B sub-family of nuclear receptors superfamily.