Ultraviolet light‐responsive element (TGACAACA,) ‐binding proteins in cells of xeroderma pigmentosum patients

The ultraviolet light (a) ‐responsive element (a) is an octamer sequence, TGACAACA, that shares homology with cyclic AMP‐responsive element and activator protein 1 target sequences. Because URE‐binding proteins have been shown to play a role in cellular response to DNA damage, we determined their expression and DNA‐binding activities in repair‐deficient cells. Of the complementation groups tested, only xeroderma pig‐mentosum (a) ‐C cells induced expression of c‐jun after UV irradiation; this correlated with XP‐C binding to the URE and resembled the pattern observed with normal human fibroblasts. In other cases either a decrease (XP‐A) or no change (XP‐D) in URE‐binding activities was noticed, which may be associated with decreased c‐fos and poor c‐jun expression after UV irradiation. That XP‐C cells were the only complementation group exhibiting URE‐binding activities similar to those of repair‐proficient cells points to the possible correlation between proper repair of transcriptionally active genes and the expression and activities of proteins implicated in the cellular response to UV irradiation. ©1995 Wiley‐Liss, Inc.