The Saccharomyces cerevisiae AP-1 protein discriminates between oxidative stress elicited by the oxidants H2O2 and diamide.
The Saccharomyces cerevisiae AP-1 protein (yAP-1) is a key mediator of oxidative stress tolerance. Transcriptional activation by yAP-1 has been shown to be inducible by exposure of cells to H2O2 and diamide, among other oxidative stress eliciting compounds. Here we define the segments of the yAP-1 protein that are required to respond to this environmental challenge. Western blotting analyses indicated that levels of yAP-1 do not change during oxidative stress. Deletion mutagenesis and gene fusion experiments indicate that two different segments of yAP-1 are required for oxidative stress inducibility. These two domains function differentially depending on the type of oxidant used to generate oxidative stress. Three repeated cysteine-serine-glutamate sequences located in the carboxyl terminus are required for normal regulation of yAP-1 function during oxidative stress. Replacement of these cysteine-serine-glutamate repeats by alanine residues does not similarly affect H2O2 and diamide regulation of yAP-1 function. While yAP-1 transactivation is enhanced by exposure to either H2O2 or diamide, the protein responds to the oxidative stress produced by these compounds in nonidentical ways.
Wemmie
J A
JA
Department of Physiology and Biophysics, University of Iowa, Iowa City, Iowa 52242, USA.
Steggerda
S M
SM
Moye-Rowley
W S
WS
D001426:Bacterial Proteins / Q000235:genetics; D003001:Cloning, Molecular; D003958:Diamide / Q000494:pharmacology*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D016297:Mutagenesis, Site-Directed; D018384:Oxidative Stress; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D017384:Sequence Deletion; D012697:Serine Endopeptidases / Q000235:genetics; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism*; D000099160:LexA Repressor Protein
D001426:Bacterial Proteins; D003958:Diamide; D005656:Fungal Proteins; D006861:Hydrogen Peroxide; D012697:Serine Endopeptidases; D018808:Transcription Factor AP-1; D000099160:LexA Repressor Protein