INTERACTION OF THE GATA FACTOR GLN3P WITH THE NITROGEN REGULATOR URE2P IN SACCHAROMYCES-CEREVISIAE

We used cells carrying plasmids causing the overproduction of Gln3p, U re2p, or both of these proteins to elucidate the ability of Ure2p to p revent the activation of gene expression by Gln3p in cells growing in a glutamine-containing medium. Our results indicate that Ure2p probabl y does not interfere with the binding of the GATA factor Gln3p to GATA AG sites but acts directly on Gln3p to block its ability to activate t ranscription.