ASSOCIATIONS OF UBE21 WITH RAD52, UBL1, P53, AND RAD51 PROTEINS IN A YEAST 2-HYBRID SYSTEM

The yeast RAD52-dependent pathway is involved in DNA recombination and double-strand break repair. Yeast ubiquitin-conjugating enzyme UBCS p articipates in S- and M-phase cyclin degradation and mitotic control. Using the human RAD52 protein as the ''bait'' in a yeast two-hybrid sy stem, we have identified a human homolog of yeast UBCS, designated UBE 2I, that interacts with RAD52, RAD5I, p53, and a ubiquitin-like protei n UBL1. These interactions are UBE2I-specific, since another DNA repai r-related ubiquitin-conjugating enzyme, RAD6 (UBC2), does not interact with these proteins. The interaction of UBE2I with RAD52 is mediated by RAD52's self-association region. These results suggest that the RAD 52-dependent processes, cell cycle control, p53-mediated pathway(s), a nd ubiquitination interact through human UBE2I. (C) 1996 Academic Pres s, Inc.