Cytosolic aspartate aminotransferase (AspAT, EC 2.6.1.1; ASP5) of Saccharomyces cerevisiae, a PLP-dependent class-I aminotransferase that interconverts L-aspartate + 2-oxoglutarate and oxaloacetate + L-glutamate. Aat2 is a major source of aspartate in the characterized growth conditions: catalytic-site mutants are aspartate auxotrophs and deletion almost abolishes newly synthesized aspartate in the tested nitrogen-starvation tracing experiment. Aat2 is mostly cytosolic in glucose-grown cells but is targeted to peroxisomes in oleate-grown cells, where it is not required for beta-oxidation. Independently of its catalytic activity, a fraction of Aat2 associates with 60S ribosomal subunits and restrains Gcn2 activation and eIF2alpha phosphorylation during oxidative stress (moonlighting function).
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0003824 catalytic activity | IEA GO_REF:0000002 | MODIFY | Summary: The broad molecular-function annotation is true; the characterized or conserved L-aspartate:2-oxoglutarate transaminase activity is the informative activity. Reason: Refine to L-aspartate:2-oxoglutarate transaminase activity, already supported elsewhere in this review. This is term specificity, not a rejection of the original evidence. Proposed replacements: L-aspartate:2-oxoglutarate transaminase activity Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt SIMILARITY: Belongs to the class-I pyridoxal-phosphate-dependent |
| GO:0004069 L-aspartate:2-oxoglutarate transaminase activity | IBA GO_REF:0000033 | ACCEPT | Summary: PAINT IBA for aspartate transaminase activity in the cytosolic AspAT (GOT1) clade; Aat2 has its own direct evidence (SGD:S000004017 appears among the donors, as expected). Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:1859361 The single (cytosolic) aspartate aminotransferase was purified in high yield from baker's yeast (Saccharomyces cerevisiae). PMID:9288922 We demonstrate that the gene AAT2 codes for the cytosolic and peroxisomal AAT activities. |
| GO:0004069 L-aspartate:2-oxoglutarate transaminase activity | IDA PMID:1859361 The amino acid sequence of the aspartate aminotransferase fr... | ACCEPT | Summary: Cronin et al. purified the single cytosolic AspAT from baker's yeast and sequenced it, identifying the protein encoded by AAT2. Supporting Evidence: PMID:1859361 The single (cytosolic) aspartate aminotransferase was purified in high yield from baker's yeast (Saccharomyces cerevisiae). file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; |
| GO:0004069 L-aspartate:2-oxoglutarate transaminase activity | IEA GO_REF:0000120 | ACCEPT | Summary: EC 2.6.1.1/RHEA:21824 mapping from the UniProt catalytic activity; correct. Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:1859361 The single (cytosolic) aspartate aminotransferase was purified in high yield from baker's yeast (Saccharomyces cerevisiae). PMID:9288922 We demonstrate that the gene AAT2 codes for the cytosolic and peroxisomal AAT activities. |
| GO:0004069 L-aspartate:2-oxoglutarate transaminase activity | IMP PMID:9288922 Cytosolic aspartate aminotransferase encoded by the AAT2 gen... | ACCEPT | Summary: Verleur et al. showed that disruption of AAT2 eliminates both cytosolic and peroxisomal AspAT activity. Supporting Evidence: PMID:9288922 We demonstrate that the gene AAT2 codes for the cytosolic and peroxisomal AAT activities. file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; |
| GO:0004069 L-aspartate:2-oxoglutarate transaminase activity | ISS GO_REF:0000024 | ACCEPT | Summary: ISS from chicken AspAT (P00508); Aat2 is a canonical class-I AspAT with direct biochemical evidence. Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:1859361 The single (cytosolic) aspartate aminotransferase was purified in high yield from baker's yeast (Saccharomyces cerevisiae). PMID:9288922 We demonstrate that the gene AAT2 codes for the cytosolic and peroxisomal AAT activities. |
| GO:0004069 L-aspartate:2-oxoglutarate transaminase activity | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (ASPARAGINE-BIOSYNTHESIS-1 (L-asparagine biosynthesis I)) asserting AspAT activity for Aat2; correct, and Aat2 is the major cytosolic isozyme carrying this reaction. Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:1859361 The single (cytosolic) aspartate aminotransferase was purified in high yield from baker's yeast (Saccharomyces cerevisiae). PMID:9288922 We demonstrate that the gene AAT2 codes for the cytosolic and peroxisomal AAT activities. |
| GO:0004069 L-aspartate:2-oxoglutarate transaminase activity | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (ASPARAGINE-DEG2-PWY (asparagine degradation)) asserting AspAT activity for Aat2; correct, and Aat2 is the major cytosolic isozyme carrying this reaction. Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:1859361 The single (cytosolic) aspartate aminotransferase was purified in high yield from baker's yeast (Saccharomyces cerevisiae). PMID:9288922 We demonstrate that the gene AAT2 codes for the cytosolic and peroxisomal AAT activities. |
| GO:0004069 L-aspartate:2-oxoglutarate transaminase activity | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (ASPARTATESYN-PWY (L-aspartate biosynthesis)) asserting AspAT activity for Aat2; correct, and Aat2 is the major cytosolic isozyme carrying this reaction. Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:1859361 The single (cytosolic) aspartate aminotransferase was purified in high yield from baker's yeast (Saccharomyces cerevisiae). PMID:9288922 We demonstrate that the gene AAT2 codes for the cytosolic and peroxisomal AAT activities. |
| GO:0004069 L-aspartate:2-oxoglutarate transaminase activity | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (ASPBIO-PWY (L-aspartate biosynthesis)) asserting AspAT activity for Aat2; correct, and Aat2 is the major cytosolic isozyme carrying this reaction. Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:1859361 The single (cytosolic) aspartate aminotransferase was purified in high yield from baker's yeast (Saccharomyces cerevisiae). PMID:9288922 We demonstrate that the gene AAT2 codes for the cytosolic and peroxisomal AAT activities. |
| GO:0004069 L-aspartate:2-oxoglutarate transaminase activity | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (P4-PWY-1 (superpathway of lysine, threonine and methionine biosynthesis)) asserting AspAT activity for Aat2; correct, and Aat2 is the major cytosolic isozyme carrying this reaction. Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:1859361 The single (cytosolic) aspartate aminotransferase was purified in high yield from baker's yeast (Saccharomyces cerevisiae). PMID:9288922 We demonstrate that the gene AAT2 codes for the cytosolic and peroxisomal AAT activities. |
| GO:0004069 L-aspartate:2-oxoglutarate transaminase activity | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (PWY3O-7 (L-homoserine biosynthesis)) asserting AspAT activity for Aat2; correct, and Aat2 is the major cytosolic isozyme carrying this reaction. Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:1859361 The single (cytosolic) aspartate aminotransferase was purified in high yield from baker's yeast (Saccharomyces cerevisiae). PMID:9288922 We demonstrate that the gene AAT2 codes for the cytosolic and peroxisomal AAT activities. |
| GO:0004069 L-aspartate:2-oxoglutarate transaminase activity | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (THRESYN-PWY (superpathway of L-threonine biosynthesis)) asserting AspAT activity for Aat2; correct, and Aat2 is the major cytosolic isozyme carrying this reaction. Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:1859361 The single (cytosolic) aspartate aminotransferase was purified in high yield from baker's yeast (Saccharomyces cerevisiae). PMID:9288922 We demonstrate that the gene AAT2 codes for the cytosolic and peroxisomal AAT activities. |
| GO:0005737 cytoplasm | IEA GO_REF:0000044 | MODIFY | Summary: The cytoplasmic annotation is correct; cytosol is the supported location of the represented soluble enzyme. Reason: Refine the broad cytoplasm term to cytosol, already supported for this gene. Conditional filament assembly or additional organelles are assessed separately. Proposed replacements: cytosol Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:9288922}. PMID:9288922 Whereas virtually all cellular AAT activity was peroxisomal in oleate-grown cells, we found that in glucose-grown cells most of the AAT activity resided in the cytosol. |
| GO:0005777 peroxisome | IDA PMID:9288922 Cytosolic aspartate aminotransferase encoded by the AAT2 gen... | ACCEPT | Summary: Aat2 supplies the directly measured peroxisomal aspartate aminotransferase activity in oleate-grown yeast. Reason: The active enzyme changes compartment with carbon source. This is a core enzyme localization under the assayed condition; normal beta-oxidation in aat2 mutants shows that localization does not establish an obligatory peroxisomal redox-shuttle role. Supporting Evidence: PMID:9288922 Whereas virtually all cellular AAT activity was peroxisomal in oleate-grown cells, we found that in glucose-grown cells most of the AAT activity resided in the cytosol. PMID:9288922 These results indicate that AAT2 is not essential for the peroxisomal NAD(H) redox shuttle. |
| GO:0005777 peroxisome | IEA GO_REF:0000044 | ACCEPT | Summary: Aat2 supplies the directly measured peroxisomal aspartate aminotransferase activity in oleate-grown yeast. Reason: The active enzyme changes compartment with carbon source. This is a core enzyme localization under the assayed condition; normal beta-oxidation in aat2 mutants shows that localization does not establish an obligatory peroxisomal redox-shuttle role. Supporting Evidence: PMID:9288922 Whereas virtually all cellular AAT activity was peroxisomal in oleate-grown cells, we found that in glucose-grown cells most of the AAT activity resided in the cytosol. |
| GO:0005777 peroxisome | IMP PMID:9288922 Cytosolic aspartate aminotransferase encoded by the AAT2 gen... | ACCEPT | Summary: Aat2 supplies the directly measured peroxisomal aspartate aminotransferase activity in oleate-grown yeast. Reason: The active enzyme changes compartment with carbon source. This is a core enzyme localization under the assayed condition; normal beta-oxidation in aat2 mutants shows that localization does not establish an obligatory peroxisomal redox-shuttle role. Supporting Evidence: PMID:9288922 We demonstrate that the gene AAT2 codes for the cytosolic and peroxisomal AAT activities. PMID:9288922 Whereas virtually all cellular AAT activity was peroxisomal in oleate-grown cells, we found that in glucose-grown cells most of the AAT activity resided in the cytosol. |
| GO:0005829 cytosol | IBA GO_REF:0000033 | ACCEPT | Summary: PAINT IBA (is_active_in cytosol) for the GOT1-like clade; matches the experimental cytosolic localisation of Aat2. Supporting Evidence: PMID:9288922 Whereas virtually all cellular AAT activity was peroxisomal in oleate-grown cells, we found that in glucose-grown cells most of the AAT activity resided in the cytosol. PMID:1859361 The single (cytosolic) aspartate aminotransferase was purified in high yield from baker's yeast (Saccharomyces cerevisiae). |
| GO:0005829 cytosol | IDA PMID:9288922 Cytosolic aspartate aminotransferase encoded by the AAT2 gen... | ACCEPT | Summary: Fractionation in glucose-grown cells: most AspAT activity resided in the cytosol and is encoded by AAT2. Supporting Evidence: PMID:9288922 Whereas virtually all cellular AAT activity was peroxisomal in oleate-grown cells, we found that in glucose-grown cells most of the AAT activity resided in the cytosol. PMID:9288922 We demonstrate that the gene AAT2 codes for the cytosolic and peroxisomal AAT activities. |
| GO:0005829 cytosol | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (ASPARAGINE-BIOSYNTHESIS-1 (L-asparagine biosynthesis I)) cytosolic placement; correct for Aat2. Supporting Evidence: PMID:9288922 Whereas virtually all cellular AAT activity was peroxisomal in oleate-grown cells, we found that in glucose-grown cells most of the AAT activity resided in the cytosol. |
| GO:0005829 cytosol | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (ASPARAGINE-DEG2-PWY (asparagine degradation)) cytosolic placement; correct for Aat2. Supporting Evidence: PMID:9288922 Whereas virtually all cellular AAT activity was peroxisomal in oleate-grown cells, we found that in glucose-grown cells most of the AAT activity resided in the cytosol. |
| GO:0005829 cytosol | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (ASPARTATESYN-PWY (L-aspartate biosynthesis)) cytosolic placement; correct for Aat2. Supporting Evidence: PMID:9288922 Whereas virtually all cellular AAT activity was peroxisomal in oleate-grown cells, we found that in glucose-grown cells most of the AAT activity resided in the cytosol. |
| GO:0005829 cytosol | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (ASPBIO-PWY (L-aspartate biosynthesis)) cytosolic placement; correct for Aat2. Supporting Evidence: PMID:9288922 Whereas virtually all cellular AAT activity was peroxisomal in oleate-grown cells, we found that in glucose-grown cells most of the AAT activity resided in the cytosol. |
| GO:0005829 cytosol | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (P4-PWY-1 (superpathway of lysine, threonine and methionine biosynthesis)) cytosolic placement; correct for Aat2. Supporting Evidence: PMID:9288922 Whereas virtually all cellular AAT activity was peroxisomal in oleate-grown cells, we found that in glucose-grown cells most of the AAT activity resided in the cytosol. |
| GO:0005829 cytosol | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (PWY3O-7 (L-homoserine biosynthesis)) cytosolic placement; correct for Aat2. Supporting Evidence: PMID:9288922 Whereas virtually all cellular AAT activity was peroxisomal in oleate-grown cells, we found that in glucose-grown cells most of the AAT activity resided in the cytosol. |
| GO:0005829 cytosol | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (THRESYN-PWY (superpathway of L-threonine biosynthesis)) cytosolic placement; correct for Aat2. Supporting Evidence: PMID:9288922 Whereas virtually all cellular AAT activity was peroxisomal in oleate-grown cells, we found that in glucose-grown cells most of the AAT activity resided in the cytosol. |
| GO:0006103 2-oxoglutarate metabolic process | ISS GO_REF:0000024 | ACCEPT | Summary: The aminotransferase directly consumes or produces 2-oxoglutarate in its core reaction. Reason: This is participation in 2-oxoglutarate metabolism through the enzyme chemistry, not an indirect phenotype; the broad process is appropriate because the physiological direction is context dependent. Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; |
| GO:0006520 amino acid metabolic process | IEA GO_REF:0000002 | MODIFY | Summary: The enzyme directly catalyzes amino-acid metabolism; the established reaction-specific process is more informative. Reason: Retain the biological claim and refine to the supported biosynthetic or catabolic processes already represented in this review. Proposed replacements: L-aspartate biosynthetic process Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; |
| GO:0006530 L-asparagine catabolic process | RCA GO_REF:0000123 | KEEP AS NON CORE | Summary: Aspartate transamination is the downstream carbon-skeleton conversion after asparaginase releases aspartate. Reason: An enzyme can participate in asparagine catabolism without binding asparagine itself. The reviewed pathway and reaction chemistry support a secondary role; isozyme-specific compartmental transport and quantitative flux are not established by the generic pathway import. Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:36040324 Intracellular aspartate is converted to glutamate and oxaloacetate, which are easily utilised by the cell through the central nitrogen metabolism. |
| GO:0006531 aspartate metabolic process | ISS GO_REF:0000024 | MODIFY | Summary: Aspartate metabolism is correct, with more specific supported directional processes. Reason: Refine the broad process using the native biosynthetic role or the supported inherited catabolic direction; reversibility does not imply equal net flux in all conditions. Proposed replacements: L-aspartate biosynthetic process Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:33397945 Loss of Aat1p reduced [U-13C]-aspartate modestly, whereas synthesis of [U-13C]-aspartate was almost completely abolished in aat2Ξ cells (Fig. 6b), suggesting that Aat2p is the major enzyme for aspartate synthesis under nitrogen starvation. |
| GO:0006531 aspartate metabolic process | RCA GO_REF:0000123 | MODIFY | Summary: Aspartate metabolism is correct, with more specific supported directional processes. Reason: Refine the broad process using the native biosynthetic role or the supported inherited catabolic direction; reversibility does not imply equal net flux in all conditions. Proposed replacements: L-aspartate biosynthetic process Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:33397945 Loss of Aat1p reduced [U-13C]-aspartate modestly, whereas synthesis of [U-13C]-aspartate was almost completely abolished in aat2Ξ cells (Fig. 6b), suggesting that Aat2p is the major enzyme for aspartate synthesis under nitrogen starvation. |
| GO:0006532 L-aspartate biosynthetic process | IBA GO_REF:0000033 | ACCEPT | Summary: PAINT IBA for L-aspartate biosynthesis in the cytosolic AspAT clade; Aat2 is the major source of aspartate in yeast. Supporting Evidence: PMID:33397945 Loss of Aat1p reduced [U-13C]-aspartate modestly, whereas synthesis of [U-13C]-aspartate was almost completely abolished in aat2Ξ cells (Fig. 6b), suggesting that Aat2p is the major enzyme for aspartate synthesis under nitrogen starvation. PMID:35621265 Non-catalytic AAT2 mutants are auxotrophic for aspartate and well expressed. |
| GO:0006532 L-aspartate biosynthetic process | IMP PMID:15780654 Metabolic-flux and network analysis in fourteen hemiascomyce... | ACCEPT | Summary: 13C metabolic-flux analysis of compartmentation of amino acid biosynthesis (abstract-only; deferring to the curator on the mutant analysis). Consistent with aat2 mutants being the major aspartate-synthesis defect. Supporting Evidence: PMID:15780654 Firstly, we found that compartmentation of amino acid biosynthesis in most species was identical to that in Saccharomyces cerevisiae. PMID:33397945 Loss of Aat1p reduced [U-13C]-aspartate modestly, whereas synthesis of [U-13C]-aspartate was almost completely abolished in aat2Ξ cells (Fig. 6b), suggesting that Aat2p is the major enzyme for aspartate synthesis under nitrogen starvation. |
| GO:0006532 L-aspartate biosynthetic process | IMP PMID:9288922 Cytosolic aspartate aminotransferase encoded by the AAT2 gen... | ACCEPT | Summary: Verleur et al. aat2 disruption (abstract-only; curator-read). Independently, non-catalytic aat2 alleles are aspartate auxotrophs and aat2 deletion abolishes de novo aspartate synthesis under nitrogen starvation. Supporting Evidence: PMID:9288922 We demonstrate that the gene AAT2 codes for the cytosolic and peroxisomal AAT activities. PMID:35621265 Non-catalytic AAT2 mutants are auxotrophic for aspartate and well expressed. PMID:33397945 Loss of Aat1p reduced [U-13C]-aspartate modestly, whereas synthesis of [U-13C]-aspartate was almost completely abolished in aat2Ξ cells (Fig. 6b), suggesting that Aat2p is the major enzyme for aspartate synthesis under nitrogen starvation. |
| GO:0006532 L-aspartate biosynthetic process | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (ASPBIO-PWY) for L-aspartate biosynthesis; correct and supported experimentally. Supporting Evidence: PMID:33397945 Loss of Aat1p reduced [U-13C]-aspartate modestly, whereas synthesis of [U-13C]-aspartate was almost completely abolished in aat2Ξ cells (Fig. 6b), suggesting that Aat2p is the major enzyme for aspartate synthesis under nitrogen starvation. PMID:35621265 Non-catalytic AAT2 mutants are auxotrophic for aspartate and well expressed. |
| GO:0006536 glutamate metabolic process | ISS GO_REF:0000024 | ACCEPT | Summary: Glutamate is directly consumed or produced by the core transamination reaction. Reason: The enzyme performs glutamate metabolism; a generic co-substrate designation does not make this chemistry non-core. A single universal net direction is not inferred. Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:33397945 Loss of Aat1p reduced [U-13C]-aspartate modestly, whereas synthesis of [U-13C]-aspartate was almost completely abolished in aat2Ξ cells (Fig. 6b), suggesting that Aat2p is the major enzyme for aspartate synthesis under nitrogen starvation. |
| GO:0006566 L-threonine metabolic process | RCA GO_REF:0000123 | MODIFY | Summary: The reviewed pathway contribution is to the biosynthetic direction through aspartate and homoserine, not to all threonine metabolism. Reason: The enzyme supplies the aspartate-forming catalytic step in the specified biosynthetic superpathway. Refine the broad metabolic term to L-threonine biosynthetic process; no threonine catabolic activity or quantitative branch flux is inferred. Proposed replacements: L-threonine biosynthetic process Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:10509015 The HOM3 gene of Saccharomyces cerevisiae encodes aspartate kinase, which catalyses the first step in the branched pathway leading to the synthesis of threonine and methionine from aspartate. |
| GO:0008483 transaminase activity | IEA GO_REF:0000002 | MODIFY | Summary: The broad molecular-function annotation is true; the characterized or conserved L-aspartate:2-oxoglutarate transaminase activity is the informative activity. Reason: Refine to L-aspartate:2-oxoglutarate transaminase activity, already supported elsewhere in this review. This is term specificity, not a rejection of the original evidence. Proposed replacements: L-aspartate:2-oxoglutarate transaminase activity Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; |
| GO:0009090 L-homoserine biosynthetic process | RCA GO_REF:0000123 | KEEP AS NON CORE | Summary: Aspartate formation supplies the substrate for the Hom3-Hom2-Hom6 sequence in the reviewed oxaloacetate-to-homoserine route. Reason: Retain the existing computational pathway contribution as secondary. Describing Hom3 as the first step from aspartate does not exclude the upstream aspartate-forming reaction when the pathway starts at oxaloacetate. This does not assert dedicated homoserine regulation or equal isozyme-specific flux. Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:10509015 The HOM3 gene of Saccharomyces cerevisiae encodes aspartate kinase, which catalyses the first step in the branched pathway leading to the synthesis of threonine and methionine from aspartate. |
| GO:0009090 L-homoserine biosynthetic process | RCA GO_REF:0000123 | KEEP AS NON CORE | Summary: Aspartate formation supplies the substrate for the Hom3-Hom2-Hom6 sequence in the reviewed oxaloacetate-to-homoserine route. Reason: Retain the existing computational pathway contribution as secondary. Describing Hom3 as the first step from aspartate does not exclude the upstream aspartate-forming reaction when the pathway starts at oxaloacetate. This does not assert dedicated homoserine regulation or equal isozyme-specific flux. Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; PMID:10509015 The HOM3 gene of Saccharomyces cerevisiae encodes aspartate kinase, which catalyses the first step in the branched pathway leading to the synthesis of threonine and methionine from aspartate. |
| GO:0030170 pyridoxal phosphate binding | IEA GO_REF:0000002 | ACCEPT | Summary: Pyridoxal phosphate binding is integral to the aminotransferase catalytic mechanism. Reason: The cofactor-binding property is core to this enzyme, not peripheral merely because it is not an independent reaction. Direct target biochemical evidence, where available, and conserved PLP-dependent architecture support the claim. Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Name=pyridoxal 5'-phosphate; Xref=ChEBI:CHEBI:597326; |
| GO:0032938 negative regulation of translation in response to oxidative stress | IMP PMID:35621265 Cytosolic aspartate aminotransferase moonlights as a ribosom... | MODIFY | Summary: Aat2 restrains excessive Gcn2-dependent translational repression during peroxide stress, independently of its aminotransferase activity. Reason: Full-text polysome profiles and catalytic-dead rescue support maintenance of translation during oxidative stress, opposite to the negative direction in the existing term. Refine to positive regulation of translation with the peroxide context explicitly retained; untreated translation was similar and universal basal activation is not asserted. Proposed replacements: positive regulation of translation Supporting Evidence: PMID:35621265 Polysome profile analysis revealed that translation was similar in untreated aat2β and wild-type (parent) cells, but ribosome run-off caused by addition of H2O2 was more acute in aat2β at lower concentrations of peroxide PMID:35621265 binding of catalytically inactive Aat2 to ribosomes is sufficient to restore normal activation of Gcn2 and the global translational repression response to acute stress |
| GO:0043023 ribosomal large subunit binding | IDA PMID:35621265 Cytosolic aspartate aminotransferase moonlights as a ribosom... | KEEP AS NON CORE | Summary: Polysome and EDTA-dissociation profiling showed Aat2 binds predominantly 60S subunits; catalytically inactive mutants retain this association. Reason: Moonlighting ribosome association; non-core relative to aminotransferase activity. Supporting Evidence: PMID:35621265 EDTA treatment to separate the ribosomal subunits further indicated that Aat2 predominantly binds to 60S (large) subunits PMID:35621265 Aat2 therefore has a separate ribosome-associated translational regulatory or 'moonlighting' function that modulates the ISR independent of its aspartate aminotransferase activity. |
| GO:0070981 L-asparagine biosynthetic process | RCA GO_REF:0000123 | KEEP AS NON CORE | Summary: Aspartate formation is the immediate substrate-supplying reaction in the represented AspAT-to-asparagine-synthetase route. Reason: Retain the reviewed pathway contribution as secondary to aspartate synthesis; AspAT does not perform amidation, and this annotation does not establish equal Aat1/Aat2 flux or every downstream amino-acid pathway. Supporting Evidence: file:yeast/AAT2/AAT2-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; |
Loading supporting contentβ¦
Download this section (compressed HTML)Q: What mechanism links ribosome-bound Aat2 to dampening of Gcn2 activation, and is it conserved for mammalian GOT1?
Q: Does peroxisomal Aat2 contribute to any redox shuttle when Mdh3 is limiting?
Cytosolic aspartate aminotransferase involved in the metabolism of nitrogen and amino acids such as aspartate; localizes to and functions in peroxisomes in oleate-grown cells; moonlighting role as a ribosome-associated protein that modulates translation in response to stress
Loading supporting contentβ¦
Download this section (compressed HTML)Loading supporting contentβ¦
Download this section (compressed HTML)