Tumor necrosis factor-α (TNFα) is a cytokine that induces pleiotropic inflammatory reactions. Soluble TNFα is released from its membrane-bound precursor by TNFα converting enzyme (TACE)/a disintegrin and metalloproteinase 17 (ADAM17). We have recently cloned the mouse TACE complete cDNA and the 5′ flanking promoter region of the gene. Two versions of the mouse TACE cDNA having a coding region of 2541bp were obtained: one was about 4.1kb and the other was 4.4kb in length, in which only the length of the 3′ UTR was different. Rapid amplification of 5′ cDNA ends suggested that there were multiple transcriptional start sites. From the coding sequence, 827 amino acids were deduced which were 91.9 % identical to those of human TACE. Northern blot analysis indicated that the major transcript was approx. 4.4kb product in the mouse. The mouse TACE mRNA was ubiquitously expressed, and was particularly high in the lung. The proximal promoter contained multiple AP2 and Sp1 transcription factor binding sites and included a GC box and a CCAAT box, but lacked a consensus TATA box. Reporter gene analysis using RAW264.7 cells showed that the fragment at nt −290 to −1 from the translation start site has a strong promoter activity, and appeared to be essential for transcription of the mouse TACE mRNA. Finally, we found that the mouse TACE promoter at nt −2304 to −1 also worked in NIH3T3, 3T3L1 and C6 cell lines.