Structure, mapping, and expression of fisp-12, a growth factor-inducible gene encoding a secreted cysteine-rich...

We have characterized a growth factor-inducible gene, fisp-12, previously isolated by differential screening of a lambda complementary DNA library of RNA from serum-stimulated NIH 3T3 cells, and have shown that it encodes a cysteine-rich secreted protein of 348 amino acids. The induction of fisp-12 mRNA is rapid and remains for at least 8 h at a high level of expression. The increased level of fisp-12 mRNA following serum stimulation is mainly due to transcriptional activation. Studies on the genomic structure reveal that the fisp-12 transcription unit is 3.1 kilobases long and split into five exons. The 5' flanking region does not contain serum-responsive elements normally found in other immediate early genes. Immunoprecipitation analyses show that the protein is rapidly induced following serum stimulation and that it is efficiently secreted in an unglycosylated form to the medium. The fisp-12 gene maps to the [10A3-10B1] region of the murine genome.