Detection of antagonistic cellular regulatory functions by the gene-gene interference method in yeast.

It was previously assumed that a new genetic method in yeast, termed gene-gene interference, leads to the selection of genes that antagonize, and/or are antagonized by, the particular reference gene used for their selection (Daniel 1993). In this paper two pieces of evidence are advanced in favour of this view. Firstly, the reconstitution of a system of known antagonistic genes was shown to be detectable by the gene-gene interference method. Secondly, since ART1, a new gene selected in reference to the protein kinase A gene, has been shown to contain in its deduced polypeptide a putative site for phosphorylation by protein kinase A, a mutagenesis study directed toward this putative site has been performed. Two phenotypes-in vivo filamenting activity and gene-gene interference relative to the protein kinase A gene-were tested with the various mutations thus obtained and found to be consistent with the hypothesis that, under physiological conditions, phosphorylation by protein kinase A exerts an inhibitory effect on Art1 activity. The relevance of these findings on the mechanisms and potential applications of the gene-gene interference phenomenon is discussed.