PUT4/YOR348C Summary Help

Standard Name PUT4
Systematic Name YOR348C
Feature Type ORF, Verified
Description Proline permease; required for high-affinity transport of proline; also transports the toxic proline analog azetidine-2-carboxylate (AzC); PUT4 transcription is repressed in ammonia-grown cells (1, 2 and see Summary Paragraph)
Name Description Proline UTilization
Chromosomal Location
ChrXV:988782 to 986899 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All PUT4 GO evidence and references
  View Computational GO annotations for PUT4
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 8 genes
Classical genetics
Large-scale survey
35 total interaction(s) for 31 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 2
  • Two-hybrid: 4

Genetic Interactions
  • Dosage Growth Defect: 1
  • Negative Genetic: 14
  • Phenotypic Enhancement: 1
  • Positive Genetic: 8
  • Synthetic Lethality: 5

Expression Summary
Length (a.a.) 627
Molecular Weight (Da) 68,787
Isoelectric Point (pI) 7.47
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXV:988782 to 986899 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1884 988782..986899 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | TCDB | UniProtKB
Primary SGDIDS000005875

Proline is an amino acid that is not only required for protein synthesis but can also serve as a nitrogen source. Although proline is the least-preferred nitrogen source for many lab strains of S. cerevisiae, it is the most abundant source of nitrogen in grapes, the natural environment of wild yeast (3). When more optimal sources of nitrogen are unavailable, S. cerevisiae cells degrade proline into glutamate via the proline utilization pathway, shown here (4, 5). In the mitochondria, proline is first converted into delta-1-pyrroline-5-carboxylate (P5C) by the PUT1 gene product, proline oxidase (EC Then, P5C is processed by the delta-1-pyrroline-5-carboxylate dehydrogenase (EC Put2p into glutamate (4).

Proline uptake is carried out mainly by two nitrogen-regulated permeases, the general amino acid permease Gap1p (6) and the high-affinity proline permease Put4p (7). The PUT4 gene product facilitates the import not only of proline, but of alanine and glycine as well (8). Put4p also mediates the transport of gamma-amino butyric acid (9, 10) and the toxic proline analog azetidine-2-carboxylate (2). Null mutations in PUT4 do not prevent growth on high concentrations of proline due to proline uptake by low affinity transport systems such as Gap1p (11). In contrast, mutations in the cytoplasmic N-terminal region of Put4p impede its degradation, leading to increased alanine, glycine, and proline uptake during beer brewing (12). Because proline is not normally taken up during fermentation (1), this results in an increased fermentation rate without compromised beer quality (12).

PUT4 is regulated at the level of transcription by nitrogen catabolite repression (NCR) (13, 14), which prevents the utilization of proline as a nitrogen source if better nitrogen compounds such as ammonia, asparagine or glutamine are present. PUT4 downregulation by NCR is mediated by the transcription factors Ure2p and Dal80p (1, 15, 16). In the presence of proline and the absence of a preferred nitrogen source, NCR is released by the transcriptional activator Gln3p and the co-activator Hfi1p (16, 17). Put4p is also regulated posttranslationally. The gene products of SEC13, LST4, LST7, are LST8 are necessary for proper localization of Put4p from the Golgi to the plasma membrane (18). Additionally, the kinases Npr1p and Pho85p are required for proline permease activation, although direct phosphorylation of Put4p by these enzymes has yet to be shown (19, 1, 20). Put4p is also regulated through ubiquitination and subsequent degradation mediated by the Rsp5p ubiquitin protein ligase and the Doa4p ubiquitin isopeptidase (21, 22, 23).

Last updated: 2005-09-07 Contact SGD

References cited on this page View Complete Literature Guide for PUT4
1) Jauniaux JC, et al.  (1987) Nitrogen catabolite regulation of proline permease in Saccharomyces cerevisiae. Cloning of the PUT4 gene and study of PUT4 RNA levels in wild-type and mutant strains. Eur J Biochem 164(3):601-6
2) Andreasson C, et al.  (2004) Four permeases import proline and the toxic proline analogue azetidine-2-carboxylate into yeast. Yeast 21(3):193-9
3) Huang HL and Brandriss MC  (2000) The regulator of the yeast proline utilization pathway is differentially phosphorylated in response to the quality of the nitrogen source. Mol Cell Biol 20(3):892-9
4) Brandriss MC and Magasanik B  (1979) Genetics and physiology of proline utilization in Saccharomyces cerevisiae: enzyme induction by proline. J Bacteriol 140(2):498-503
5) Brandriss MC and Magasanik B  (1979) Genetics and physiology of proline utilization in Saccharomyces cerevisiae: mutation causing constitutive enzyme expression. J Bacteriol 140(2):504-7
6) Jauniaux JC and Grenson M  (1990) GAP1, the general amino acid permease gene of Saccharomyces cerevisiae. Nucleotide sequence, protein similarity with the other bakers yeast amino acid permeases, and nitrogen catabolite repression. Eur J Biochem 190(1):39-44
7) Vandenbol M, et al.  (1989) Nucleotide sequence of the Saccharomyces cerevisiae PUT4 proline-permease-encoding gene: similarities between CAN1, HIP1 and PUT4 permeases. Gene 83(1):153-9
8) Regenberg B, et al.  (1999) Substrate specificity and gene expression of the amino-acid permeases in Saccharomyces cerevisiae. Curr Genet 36(6):317-28
9) Bermudez Moretti M, et al.  (1998) UGA4 gene expression in Saccharomyces cerevisiae depends on cell growth conditions. Cell Mol Biol (Noisy-le-grand) 44(4):585-90
10) Andre B, et al.  (1993) Cloning and expression of the UGA4 gene coding for the inducible GABA-specific transport protein of Saccharomyces cerevisiae. Mol Gen Genet 237(1-2):17-25
11) Lasko PF and Brandriss MC  (1981) Proline transport in Saccharomyces cerevisiae. J Bacteriol 148(1):241-7
12) Omura F, et al.  (2005) Engineering of yeast put4 permease and its application to lager yeast for efficient proline assimilation. Biosci Biotechnol Biochem 69(6):1162-71
13) ter Schure EG, et al.  (2000) The role of ammonia metabolism in nitrogen catabolite repression in Saccharomyces cerevisiae. FEMS Microbiol Rev 24(1):67-83
14) Xu S, et al.  (1995) Roles of URE2 and GLN3 in the proline utilization pathway in Saccharomyces cerevisiae. Mol Cell Biol 15(4):2321-30
15) ter Schure EG, et al.  (1998) Repression of nitrogen catabolic genes by ammonia and glutamine in nitrogen-limited continuous cultures of Saccharomyces cerevisiae. Microbiology 144 ( Pt 5)():1451-62
16) Daugherty JR, et al.  (1993) Regulatory circuit for responses of nitrogen catabolic gene expression to the GLN3 and DAL80 proteins and nitrogen catabolite repression in Saccharomyces cerevisiae. J Bacteriol 175(1):64-73
17) Soussi-Boudekou S and Andre B  (1999) A co-activator of nitrogen-regulated transcription in Saccharomyces cerevisiae. Mol Microbiol 31(3):753-62
18) Roberg KJ, et al.  (1997) Control of amino acid permease sorting in the late secretory pathway of Saccharomyces cerevisiae by SEC13, LST4, LST7 and LST8. Genetics 147(4):1569-84
19) Grenson M  (1983) Study of the positive control of the general amino-acid permease and other ammonia-sensitive uptake systems by the product of the NPR1 gene in the yeast Saccharomyces cerevisiae. Eur J Biochem 133(1):141-4
20) Popova IG, et al.  (2000) [Effect of mutations in PHO85 and PHO4 genes on utilization of proline in Saccharomyces cerevisiae yeasts]. Genetika 36(12):1622-8
21) Stanbrough M and Magasanik B  (1995) Transcriptional and posttranslational regulation of the general amino acid permease of Saccharomyces cerevisiae. J Bacteriol 177(1):94-102
22) Grenson M  (1983) Inactivation-reactivation process and repression of permease formation regulate several ammonia-sensitive permeases in the yeast Saccharomyces cerevisiae. Eur J Biochem 133(1):135-9
23) Huibregtse JM, et al.  (1995) A family of proteins structurally and functionally related to the E6-AP ubiquitin-protein ligase. Proc Natl Acad Sci U S A 92(7):2563-7