UBL1, A HUMAN UBIQUITIN-LIKE PROTEIN ASSOCIATING WITH HUMAN RAD51 RAD52 PROTEINS/

The RAD51/RAD52-dependent DNA repair pathway is involved in DNA recomb ination and DNA double-strand break repair in yeast. Although many pro teins in the RAD51/RAD52-dependent DNA repair pathway have been identi fied in yeast, a novel protein(s) that functions with RAD51/RAD52 may also exist in humans. Using a yeast two-hybrid system, we have identif ied a 12-kDa protein that associates with the human RAD51 and RAD52 pr oteins. This protein shares significant amino acid homology with the y east protein SMT3, which functionally associates with the yeast mitosi s fidelity protein MIF2. It also shares moderate homology with ubiquit in and several other proteins, including the N-terminus of the RAD23 p rotein and a ubiquitin cross reacting protein. Therefore, the gene is tentatively designated UBL1 for ubiquitin-like 1. The UBL1 mRNA is exp ressed in many human tissues, most highly in testis. The UBL1 gene is mapped to chromosome 2q32.2-q33, and a related sequence may be located on chromosome 1q23-q25. (C) 1996 Academic Press, Inc.