Cloning, expression profile, and genomic organization of the mouse STAQ/A170 gene

The preferential screening of cDNA libraries derived from the mouse osteobl astic cell line MC3T3-E1 has yielded a cDNA clone encoding a 442-amino-acid protein designated STAP (signal transduction and adaptor protein), which c ontains several motifs shared among transcription factors and adaptors such as a Zn-finger like motif, a proline-rich domain, and a PEST sequence. The amino acid sequence homology search also reveals that STAP is identical to a mouse oxidative stress protein, A170, and has 90% homology with a human p62 protein that binds to the tyrosine kinase p561(lck) SH2 domain, Norther n blot analysis indicated a broad expression profile of STAP mRNA in variou s tissues and cell lines. In MC3T3-E1 cells, STAP mRNA was induced by treat ment with TGF-P, but not with BMP-S or GDF-5. Analysis of the mouse STAP ge ne isolated from the genomic library revealed that the STAP gene spans a re gion of over 11 kb and comprises eight exons. The transcription start site was identified by primer extension analysis to be located 35 bp upstream fr om the translation initiation site. Sequencing analysis of the 5' flanking region of the STAP gene revealed multiple consensus motifs/sequences for se veral DNA binding transcription factors. The STAP gene had a TATA box, but no CCAAT box. Potential Spl, AP-1, NF-ES, MyoD, and NF-kappa B binding site s were found in the 5' flanking region (1.4 kb) of the STAP gene. (C) 1999 Academic Press.