TRX1/YLR043C Summary Help

Standard Name TRX1
Systematic Name YLR043C
Alias LMA1 1
Feature Type ORF, Verified
Description Cytoplasmic thioredoxin isoenzyme; part of thioredoxin system which protects cells against oxidative and reductive stress; forms LMA1 complex with Pbi2p; acts as a cofactor for Tsa1p; required for ER-Golgi transport and vacuole inheritance; with Trx2p, facilitates mitochondrial import of small Tims Tim9p, Tim10p, Tim13p by maintaining them in reduced form; abundance increases iunder DNA replication stress; TRX1 has a paralog, TRX2, that arose from the whole genome duplication (1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and see Summary Paragraph)
Name Description ThioRedoXin
Chromosomal Location
ChrXII:232013 to 231702 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Genetic position: -7 cM
Gene Ontology Annotations All TRX1 GO evidence and references
  View Computational GO annotations for TRX1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 10 genes
Classical genetics
Large-scale survey
56 total interaction(s) for 40 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 17
  • Affinity Capture-RNA: 2
  • Affinity Capture-Western: 3
  • Biochemical Activity: 1
  • PCA: 2
  • Reconstituted Complex: 1
  • Two-hybrid: 3

Genetic Interactions
  • Dosage Rescue: 1
  • Negative Genetic: 10
  • Phenotypic Enhancement: 8
  • Synthetic Growth Defect: 2
  • Synthetic Lethality: 5
  • Synthetic Rescue: 1

Expression Summary
Length (a.a.) 103
Molecular Weight (Da) 11,235
Isoelectric Point (pI) 4.62
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXII:232013 to 231702 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Genetic position: -7 cM
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..312 232013..231702 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) | UniProtKB
Primary SGDIDS000004033

About the thioredoxin system

The thioredoxin system and glutathione/glutaredoxin system help maintain the reduced environment of the cell and play a significant role in defending the cell against oxidative stress. They also have been proposed to play a role in purine and pyrimidine biosynthesis as required for DNA synthesis, protein folding and regulation, and sulfur metabolism (11, 12).

Thioredoxins and glutaredoxins are small heat-stable proteins with redox-active cysteines that facilitate the reduction of other proteins by catalyzing cysteine thiol-disulfide exchange reactions (12). Thioredoxins contain two conserved cysteines that exist in either a reduced form as in thioredoxin-(SH)2) or in an oxidized form as in thioredoxin-S2) when they form an intramolecular disulfide bridge (12). Thioredoxins donate electrons from their active center dithiol to protein disulfide bonds (Protein-S2) that are then reduced to dithiols (Protein-(SH)2). The resulting oxidized thioredoxin disulfide is reduced directly by thioredoxin reductase with electrons donated by NADPH (12). Hence the thioredoxin reduction system consists of thioredoxin, thioredoxin reductase, and NADPH. Oxidized glutaredoxins, on the other hand, are reduced by the tripeptide glutathione (gamma-Glu-Cys-Gly, known as GSH) using electrons donated by NADPH (12). Hence the glutathione/glutaredoxin system consists of glutaredoxin, glutathione, glutathione reductase and NADPH.

S. cerevisiae contains a cytoplasmic thioredoxin system comprised of the thioredoxins Trx1p and Trx2p and the thioredoxin reductase Trr1p, and a complete mitochondrial thioredoxin system comprised of the thioredoxin Trx3p and the thioredoxin reductase Trr2p (13). Evidence suggests that the cytoplasmic thioredoxin system may have overlapping function with the glutathione/glutaredoxin system (14, 15). The mitochondrial thioredoxin system, on the other hand, does not appear to be able to substitute for either the cytoplasmic thioredoxin or glutathione/glutaredoxin systems (15). Instead, the mitochondrial thioredoxn proteins, thioredoxin (Trx3p) and thioredoxin reductase (Trr2p) have been implicated in the defense against oxidative stress generated during respiratory metabolism (2).

The two cytoplasmic thioredoxins (Trx1p and Trx2p) are believed to supply reducing equivalents to the enzymes ribonucleotide reductase (Rnr1p, Rnr2p, Rnr3p, Rnr4p) and 3'-phosphoadenosine 5'-phosphosulfate (PAPS) reductase (Met16p) (16, 17). Deletion of either TRX1 or TRX2 has no effect on cell growth or morphology (18), but, deletion of both genes affects the cell cycle, and makes the cells auxotrophic for methionine/cysteine (18, 19). Deletion of the single gene TRX2 does result in extreme sensitivity to H2O2 and is thereby believed to be involved in the response against H2O2 (20). The expression of TRX2 and TRR1 are regulated by the transcription factors Yap1p and Skn7p in response to H2O2 (20, 21).

Last updated: 2007-10-23 Contact SGD

References cited on this page View Complete Literature Guide for TRX1
1) Xu Z and Wickner W  (1996) Thioredoxin is required for vacuole inheritance in Saccharomyces cerevisiae. J Cell Biol 132(5):787-94
2) Pedrajas JR, et al.  (1999) Identification and functional characterization of a novel mitochondrial thioredoxin system in Saccharomyces cerevisiae. J Biol Chem 274(10):6366-73
3) Xu Z, et al.  (1997) A heterodimer of thioredoxin and I(B)2 cooperates with Sec18p (NSF) to promote yeast vacuole inheritance. J Cell Biol 136(2):299-306
4) Barlowe C  (1997) Coupled ER to Golgi transport reconstituted with purified cytosolic proteins. J Cell Biol 139(5):1097-108
5) Spang A and Schekman R  (1998) Reconstitution of retrograde transport from the Golgi to the ER in vitro. J Cell Biol 143(3):589-99
6) Garrido EO and Grant CM  (2002) Role of thioredoxins in the response of Saccharomyces cerevisiae to oxidative stress induced by hydroperoxides. Mol Microbiol 43(4):993-1003
7) Trotter EW and Grant CM  (2002) Thioredoxins are required for protection against a reductive stress in the yeast Saccharomyces cerevisiae. Mol Microbiol 46(3):869-78
8) Byrne KP and Wolfe KH  (2005) The Yeast Gene Order Browser: combining curated homology and syntenic context reveals gene fate in polyploid species. Genome Res 15(10):1456-61
9) Tkach JM, et al.  (2012) Dissecting DNA damage response pathways by analysing protein localization and abundance changes during DNA replication stress. Nat Cell Biol 14(9):966-76
10) Durigon R, et al.  (2012) Cytosolic thioredoxin system facilitates the import of mitochondrial small Tim proteins. EMBO Rep 13(10):916-22
11) Grant CM  (2001) Role of the glutathione/glutaredoxin and thioredoxin systems in yeast growth and response to stress conditions. Mol Microbiol 39(3):533-41
12) Holmgren A  (1989) Thioredoxin and glutaredoxin systems. J Biol Chem 264(24):13963-6
13) Trotter EW and Grant CM  (2005) Overlapping roles of the cytoplasmic and mitochondrial redox regulatory systems in the yeast Saccharomyces cerevisiae. Eukaryot Cell 4(2):392-400
14) Muller EG  (1996) A glutathione reductase mutant of yeast accumulates high levels of oxidized glutathione and requires thioredoxin for growth. Mol Biol Cell 7(11):1805-13
15) Draculic T, et al.  (2000) A single glutaredoxin or thioredoxin gene is essential for viability in the yeast Saccharomyces cerevisiae. Mol Microbiol 36(5):1167-74
16) Gonzalez Porque P, et al.  (1970) The involvement of the thioredoxin system in the reduction of methionine sulfoxide and sulfate. J Biol Chem 245(9):2371-4
17) Gonzalez Porque P, et al.  (1970) Purification of a thioredoxin system from yeast. J Biol Chem 245(9):2363-70
18) Muller EG  (1991) Thioredoxin deficiency in yeast prolongs S phase and shortens the G1 interval of the cell cycle. J Biol Chem 266(14):9194-202
19) Muller EG  (1994) Deoxyribonucleotides are maintained at normal levels in a yeast thioredoxin mutant defective in DNA synthesis. J Biol Chem 269(39):24466-71
20) Kuge S and Jones N  (1994) YAP1 dependent activation of TRX2 is essential for the response of Saccharomyces cerevisiae to oxidative stress by hydroperoxides. EMBO J 13(3):655-64
21) Morgan BA, et al.  (1997) The Skn7 response regulator controls gene expression in the oxidative stress response of the budding yeast Saccharomyces cerevisiae. EMBO J 16(5):1035-44