Identification of a HeLa mRNA fraction which corrects the mitomycin C sensitivity of irs1 cells.

The hamster cell mutant irs1 is defective in its response to DNA lesions caused by a variety of mutagens, particularly cross-linking agents. These cells have been assigned to complementation group 2 of X-ray-sensitive mutants and the mutated gene is called XRCC2(X-ray repair cross complementing). We have identified, by microinjection, a human mRNA fraction which can transiently correct the sensitivity of these cells to cross-linking agents. This fraction contains mRNAs of 3.5 kb (+/- 0.25) including, therefore, the transcript of the XRCC2 gene.