Structure and expression of TIS21, a primary response gene induced by growth factors and tumor promoters.

The TIS21 gene is a primary response gene that is induced rapidly and transiently in 3T3 cells by the tumor promoter and mitogen tetradecanoyl phorbol acetate. The predicted open reading frame of the TIS21 cDNA encodes a protein of 158 amino acids with no obvious similarity to any known protein. Antiserum prepared to TIS21 recombinant protein produced in Escherichia coli precipitates a 17-kDa protein from Swiss 3T3 cells. The 2040-nucleotide 3'-untranslated region of the cDNA includes an unusual T18 sequence. The TIS21 gene has a single 1.4-kilobase intron which interrupts the open reading frame and is otherwise identical to the cDNA sequence. The 5'-flanking sequence of the TIS21 gene contains TATA and CAAT box-type sequences, three potential Sp1 sites, two putative cyclic AMP response elements, two potential AP1 binding elements, and an AP2 element. A possible Z-DNA structure of 29 AC repeats is present 660 nucleotides from the start of transcription. Expression from a luciferase reporter construct containing a 460-nucleotide fragment of the TIS21 promoter is induced by tetradecanoyl phorbol acetate, forskolin, epidermal growth factor, and serum, despite the absence of a consensus serum response element.