Ž . Biochimica et Biophysica Acta 398 1998 9–17 Rapid report Genomic structure of Unp, a murine gene encoding a ubiquitin-specific protease Marco Di Fruscio a,b , Catherine A. Gilchrist c , Rohan T. Baker c , Douglas A. Gray a,d, ) a Ottawa Regional Cancer Centre, 501 Smyth Road, Ottawa, Ontario, Canada K1H 8L6 b Department of Biochemistry, UniÕersity of Ottawa, 451 Smyth Road, Ottawa, Ontario, Canada K1H 8M5 c Molecular Genetics Group, John Curtin School of Medical Research, Australian National UniÕersity, PO Box 334, Canberra ACT 2601, Australia d Department of Medicine, UniÕersity of Ottawa, 451 Smyth Road, Ottawa, Ontario, Canada K1H 8M5 Received 4 February 1998; accepted 5 February 1998 Abstract The murine Unp gene encodes a ubiquitin-specific protease, a member of a family of enzymes that includes the product of the human tre-2 oncogene. The Unp gene has previously been mapped to chromosome 9. We have cloned in bacteriophage a 50 kilobase region of chromosome 9 containing the Unp gene, and have determined the nucleotide sequence of the gene. The gene has 22 exons, distributed over 47.4 kb. A processed ribosomal S2 pseudogene was identified in the third intron of the Unp gene. Expression of Unp is driven by a GC-rich, ‘housekeeping’ type promoter. q 1998 Elsevier Science B.V. All rights reserved. Keywords: Ubiquitin; Protease We have previously reported the cloning of a wx cDNA derived from a gene designated Unp 1 . The sequence of the predicted Unp protein was found to strongly resemble a human oncogene, variously w x known as tre-2 or TRE17 2–4 . Like tre-2, Unp cDNA transformed NIH 3T3 fibroblasts in a nude wx wx mouse assay 5 . Unp, its human homolog Unph 6, and tre-2 are members of a family of genes related to Ž . yeast ubiquitin-specific proteases Ubp’s , or deubiq- uitinating enzymes. The tre-2 gene encodes an en- zyme that is similar to the yeast Doa4 enzyme, and wx has similar ubiquitin cleavage activity 7 . Of the yeast Ubp’s, Unp is most similar in sequence to the ) Corresponding author. Ž . yeast Ubp12 enzyme Gray, unpublished , and effi- ciently cleaves ubiquitin from substrates both in vivo Ž . and in vitro Gilchrist et al., in preparation , but unlike other known Ubp enzymes, Unp can cleave a wx ubiquitin-proline bond 8 . Because of intense recent interest in the ubiquitin Ž pathway in normal homeostasis and in cancer re- w x. viewed in Refs. 9,10 and because Unp was shown to have transforming activity in vivo, the structure and regulation of the gene is of some importance. We therefore sought to clone and sequence the Unp gene. Isolation and characterization of genomic clones. A genomic library from the 129 mouse strain was constructed by partial MboI digestion of 129 liver DNA to obtain fragments in the 15 to 20 kb range. Fragments of this size were purified from 10–40% 0167-4781r98r$19.00 q 1998 Elsevier Science B.V. All rights reserved. Ž . PII S0167-4781 98 00035-9