Showing papers on "Psychological repression published in 1979"

Nitrogen metabolite repression of nitrate reductase in Neurospora crassa: effect of the gln-1a locus.

Abstract: Nicotinamide adenine dinucleotide phosphate (reduced form)-nitrate reductase was freed from ammonium repression in a Neurospora crassa mutant having drastically lowered glutamine synthetase activity, gln-1a. The general phenomenon of nitrogen metabolite repression required glutamine or some aspect of glutamine metabolism.

Regulation of activity and synthesis of N-acetylglutamate synthase from Saccharomyces cerevisiae.

Abstract: Feedback inhibition of N-acetylgutamate synthase in a particulate fraction from Saccharomyces cerevisiae by L-arginine was synergistically enhanced by N-actylglutamate, whereas coenzyme A let to an additive enhancement of arginine inhibition. N-acetylglutamate synthase was not inhibited by polyamines, nor was the enzyme inactivated by incubation in the presence of coenzyme A and zinc ions. Evidence was obtained for the involvement of at least three different regulatory mechanisms in the expression of N-acetylglutamate synthase: arginine-specific repression, glucose repression and general amino acid control. The combined action of these control mechanisms led to a 90-fold variation in the specific activity of the enzyme.

Oxalurate transport in Saccharomyces cerevisiae.

Abstract: Oxalurate, the gratuitous inducer of the allantoin degradative enzymes, was taken into the cell by an energy-dependent active transport system with an apparent Km of 1.2 mM. Efflux of previously accumulated oxalurate was rapid, with a half-life of about 2 min. The oxalurate uptake system appears to be both constitutively produced and insensitive to nitrogen catabolite repression. The latter observations suggest that failure of oxalurate to bring about induction of allophanate hydrolase in cultures growing under repressive conditions does not result from inducer exclusion, but rather from repression of dur1,2 gene expression.