Isolation of a mouse cDNA encoding mSTI1, a stress-inducible protein containing the TPR motif

We report the isolation and sequencing of the complete 2079-bp cDNA fragment encoding mSTI1, a murine stress-inducible protein. The predicted ORF encodes a protein of 543 amino acids (aa) and Mr 62,582. The predicted protein has significant homology to stress-inducible proteins from humans (IEF SSP 3521), soybean (GMSTI), yeast (STI1) and a parasite, Leishmania donovani (LSIP). All of these proteins contain 34-aa repeat motifs, termed tetratricopeptide repeats (TPRs), that are proposed to be involved in intra- and intermolecular protein interactions. mSTI1 has ten potential TPR motifs, a putative nuclear localization signal (NLS), six potential phosphorylation sites for casein kinase II and a central proline-rich region. Western analysis detected a protein of approx. 63 kDa in all the major mouse organs and in mouse, monkey and human cell lines.