COMPLETE SEQUENCE-ANALYSIS OF A GENE (OS-9) UBIQUITOUSLY EXPRESSED INHUMAN TISSUES AND AMPLIFIED IN SARCOMAS

Amplification and overexpression of genes involved in cellular growth control occur frequently in human tumors. Using a chromosome microdiss ection-based hybrid-selection strategy, we recently identified two nov el genes (OS-9 and OS-4) within 12q13-15, a region frequently amplifie d in human cancers. We now report further characterization of the full -length OS-9 cDNA sequence. This cDNA sequence consists of 2785 bp fro m which an open reading frame (ORF) with 667 amino-acid residues was d educed. The predicted polypeptide was water soluble and acidic. We als o demonstrate that the OS-9 gene encoded a 2.8-kb mRNA transcribed in all 16 human tissues examined, suggesting that OS-9 is ubiquitously ex pressed in human tissues. OS-9 was coamplified with CDK4 in three of f ive sarcoma tissues. Homology analysis of the amino-acid sequence reve als significant similarities between OS-9 and two ORFs deduced from ge nomic sequences in Caenorhabditis elegans and Saccharomyces cerevisiae . The region of similarity extended over 200 residues (approximately o ne-third of each ORF), and eight cysteines were conserved in all three ORFs. These observations suggest that this region comprises a functio nal domain present in a novel evolutionarily conserved gene family def ined by OS-9. (C) 1996 Wiley-Liss, Inc.