I. The initial velocity of entrance of L-[14C]lysine into yeast cells appears, according to a Lineweaver-Burk plot, to be dependent on two functions. Evidence is presented showing that lysine enters the cell by two distinct systems. 2. One of these systems is the arginine permease: it has been lost in the arg-p1 mutants (canavanine-resistant, arginine permease-less) and is specifically and competitively inhibited by L-arginine with a Ki of 10-5 M identical with the Km of arginine for its permease. Its apparent affinity constant for lysine is about 2 x 10-4 M. 3. The other lysine-uptake system has a higher affinity for lysine (Km, 2.5 x 10-5 M). It is highly specific for lysine, as shown by competition experiments and by the fact that the loss of its activity by mutation (lys-p1) affects lysine uptake exclusively. 4. It is concluded: (a) that a very specific lysine permease distinct and independent of the arginine permease exists in yeast; (b) that lysine may enter the cell by means of the arginine permease, while arginine cannot use the lysine permease.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|