High impact information on PUT4

• AZC enters budding yeast Saccharomyces cerevisiae cells primarily through the general amino acid permease Gap1, not through the proline-specific permease Put4 [1].
• Northern blotting of the nontransformed and the M-gamma-A-transformed 22574d cells with gene-specific probes for the three proline transporters showed the expression of an mRNA for UGA4 in both transformed and nontransformed cells but no evidence for the expression of GAP1 or PUT4 [2].
• In the mutant, the PUT4 mRNA encoding the proline permease is not affected, whereas the DUR3 mRNA, involved in urea active transport, is strongly increased [3].
• The complete nucleotide (nt) sequence of the PUT4 gene, whose product is required for high-affinity proline active transport in the yeast Saccharomyces cerevisiae, is presented [4].
• Strains carrying the put4 mutation are defective in the high-affinity proline transport system [5].

Biological context of PUT4

• A second focus of the review is the nitrogen regulation of the general amino acid permease, Gap1p, and the proline permease, Put4p, by ubiquitin mediated intracellular protein sorting in the secretory and endosomal pathways [6].
• Put4p downregulation is counteracted by npi1 mutation that affects the cellular ubiquitination function [7].

Anatomical context of PUT4

• 2. GABA transport (Km=3.2+/-0.1 microM and Vmax=0.299+/-0.045 micromol/mg protein min) is probably mediated by a permease similar to Saccharomyces cerevisiae PUT4; this result also indicates that the isolated capillaries are metabolically active [8].

Associations of PUT4 with chemical compounds

• In yeast GABA is also incorporated by the general amino acid permease (GAP1) and the specific proline permease (PUT4) [9].
• In strains having one class of mutations (per1), ammonia inactivation of the PUT4 and GAP1 permeases did not occur, whereas glutamate and glutamine inactivation did [10].
• The transport of GABA in Saccharomyces cerevisiae is mediated by three permeases: the general amino acid permease (GAP1), the specific proline permease (PUT4) and a fairly specific GABA permease (UGA4) [11].
• Low-affinity transport was inhibited by histidine, so put4 mutants were unable to grow on a medium containing high concentrations of proline to which histidine has been added [5].
• Here we describe mutant Put4 permeases, in which up to nine lysine residues in the cytoplasmic N-terminal domain have been replaced by arginine [7].

Other interactions of PUT4

• In the yeast Saccharomyces cerevisiae, gamma-aminobutyric acid (GABA) transport is mediated by three permeases: the general amino acid permease GAP1, the proline permease PUT4 and the specific GABA permease UGA4 [12].
• The activities of arginine (Can1p), proline (Put4p) and general amino acid permease (Gap1p) are decreased more than 20-fold [13].

References