The zinc finger domain of Tzfp binds to the tbs motif located at the upstream flanking region of the Aie1 (aurora-C) kinase gene

Our previous studies showed that Aiel (aurora-C), is a novel. testis kinase belonging to the aurora kinase family (1). In this report, we describe a t estis zinc finger protein (Tzfp) that binds to the upstream flanking sequen ce of the Aiel gene. The mouse Tzfp gene, mapped to chromosome 7 B2-B3, enc odes a 465-amino acid transcription factor containing a conserved N-termina l BTB/POZ domain and three C-terminal PLZF-like C2H2 zinc fingers. The zinc finger domain of Tzfp binds to the TGTA-CAGTGT motif (Tzfp binding site, t ermed tbs) located at the upstream flanking sequence of the Aiel gene by ge l mobility shift, DNase I footprinting, and competition analyses. When the C-terminal zinc fingers of Tzfp were fused to the transactivation domain of VP16, the chimera activated transcription of a reporter construct containi ng multiple copies of the tbs. In contrast, the same chimera did not activa te the reporter gene when an essential nucleotide fifth C was mutated to A at the tbs. Furthermore, we showed that the N-terminal BTB/POZ domain of TZ FP has a repressor activity. Taken together, our results indicate that Tzfp recognizes a sequence-specific motif (tbs) and may play a role in the regu lation of the genes carrying the tbs.