Knoepfel L, Steinkühler C, Carrì M T, Rotilio G
Department of Biology, University of Rome, Tor Vergata, Rome, Italy.
Biochem Biophys Res Commun. 1994 Jun 15;201(2):871-7. doi: 10.1006/bbrc.1994.1782.
We show that thiol-groups confer redox-susceptibility to the zinc-finger transcription factor Sp1 and that this redox-susceptibility is prevented by DNA-binding and depends on zinc-coordination of the protein. Apo-Sp1 contained in metal depleted nuclear extracts of human K562 cells exhibited a markedly increased susceptibility towards oxidizing and alkylating agents, as compared to holo-Sp 1. Moreover, DNA binding of apo-Sp1, but not of the holo-protein, was dramatically decreased in the presence of GSH/GSSG ratios within the physiological range. We compared these results with the redox behaviour of two other transcription factors, OTF-1 and NF1, which was found to be different in several aspects from that of Sp1.
