We previously identified and cloned T-cell translocation gene 1 (Ttg- 1), a putative zinc finger protein, as a result of its deregulated expression in a T-cell acute lymphoblastic leukemia cell line (RPMI 8402) with a t(11;14)(p15;q11). We have now characterized its genomic organization and identified the major transcriptional start site to lie within an initiator-like motif. Ttg-1 is normally expressed in mouse brain and not in thymus. The mouse neuroblastoma cell line, N2a, also expresses Ttg-1. Antibodies raised against a TrpE-Ttg-1 fusion protein precipitate an 18-Kd nuclear protein from metabolically labeled 8402 cells. Immunofluorescence of N2a cells shows a nuclear pattern. The two potential zinc finger domains in Ttg-1 are highly homologous to similar regions in lin-11, mec-3, and lsl-1. This data suggests that Ttg-1 may be involved in gene regulation.