Got2

UniProt ID: Q8IPY3
Organism: Drosophila melanogaster
Review Status: COMPLETE
📝 Provide Detailed Feedback

Gene Description

Got2 (CG4233) encodes the mitochondrial aspartate aminotransferase (glutamate oxaloacetate transaminase 2) of Drosophila melanogaster, a homodimeric pyridoxal 5'-phosphate-dependent class I aminotransferase. In the mitochondrial matrix it reversibly converts L-glutamate and oxaloacetate into 2-oxoglutarate and L-aspartate, providing the mitochondrial arm of the malate-aspartate shuttle and a major route for aspartate production and glutamate turnover. Got2 is detected in the fly mitochondrial proteome. Genetic manipulation of GOT activity in flies alters glutamate levels, and reduced presynaptic glutamate at the larval neuromuscular junction enlarges the postsynaptic glutamate receptor field, linking this metabolic enzyme to developmental tuning of glutamatergic synapses.

Existing Annotations Review

GO Term Evidence Action Reason
GO:0003824 catalytic activity
IEA
GO_REF:0000002 		MODIFY
Summary: Generic catalytic activity from InterPro aminotransferase class I PLP-binding-site mapping.
Reason: Correct but uninformative; Got2 is an aspartate aminotransferase, a term already annotated with experimental support.
Supporting Evidence:
file:DROME/Got2/Got2-uniprot.txt
DR InterPro; IPR000796; Asp_trans.
GO:0004069 L-aspartate:2-oxoglutarate transaminase activity
IBA
GO_REF:0000033 		ACCEPT
Summary: Aspartate transaminase activity, phylogenetic inference.
Reason: Got2 sits in the mitochondrial AST subfamily (PTHR11879:SF22) with the conserved PLP lysine; consistent with experimental data.
Supporting Evidence:
file:DROME/Got2/Got2-uniprot.txt
DR PANTHER; PTHR11879:SF22; ASPARTATE AMINOTRANSFERASE, MITOCHONDRIAL; 1.
GO:0004069 L-aspartate:2-oxoglutarate transaminase activity
IDA
PMID:3106567
A genetic analysis of glutamatergic function in Drosophila. 		ACCEPT
Summary: Aspartate transaminase activity measured in fly tissues (Chase and Kankel 1987).
Reason: GOT activity directly assayed; core activity. Curators had the full text, which distinguishes the mitochondrial isozyme.
Supporting Evidence:
PMID:3106567
glutamate oxaloacetic transaminase
GO:0004069 L-aspartate:2-oxoglutarate transaminase activity
IDA
PMID:823072
Genetic analysis of aspartate aminotransferase isozymes from... 		ACCEPT
Summary: Aspartate aminotransferase isozyme GOT2 characterised electrophoretically and genetically (Grell 1976).
Reason: Grell identified GOT2 as one of the two fly AST isozymes and mapped Got2, recovering a mobility variant (Got2J).
Supporting Evidence:
PMID:823072
The aspartate aminotransferases (designated GOT1 and GOT2) are two enzymes of Drosophila melanogaster
GO:0004069 L-aspartate:2-oxoglutarate transaminase activity
IEA
GO_REF:0000003 		ACCEPT
Summary: Aspartate transaminase activity from EC mapping.
Reason: Consistent with all other evidence.
Supporting Evidence:
file:DROME/Got2/Got2-uniprot.txt
Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate;
GO:0005739 mitochondrion
HDA
PMID:16212416
Characterization of the Drosophila melanogaster mitochondria... 		ACCEPT
Summary: Mitochondrion, from the larval mitochondrial proteome (Alonso et al. 2005).
Reason: High-throughput identification in purified mitochondria; consistent with its mitochondrial subfamily.
Supporting Evidence:
PMID:16212416
we purified mitochondria from third instar Drosophila larvae
GO:0005739 mitochondrion
IBA
GO_REF:0000033 		ACCEPT
Summary: Mitochondrion, phylogenetic inference.
Reason: Mitochondrial AST subfamily; the IBA is appropriate.
Supporting Evidence:
file:DROME/Got2/Got2-uniprot.txt
DR PANTHER; PTHR11879:SF22; ASPARTATE AMINOTRANSFERASE, MITOCHONDRIAL; 1.
GO:0005739 mitochondrion
IDA
PMID:3106567
A genetic analysis of glutamatergic function in Drosophila. 		ACCEPT
Summary: Mitochondrion, from the Chase and Kankel (1987) study of fly GOT isozymes.
Reason: Core location; curators had the full text.
Supporting Evidence:
PMID:3106567
glutamate oxaloacetic transaminase
GO:0006103 2-oxoglutarate metabolic process
ISS
GO_REF:0000024 		ACCEPT
Summary: 2-oxoglutarate metabolic process, transferred by sequence similarity.
Reason: 2-Oxoglutarate is a direct substrate/product of the reaction.
Supporting Evidence:
file:DROME/Got2/Got2-uniprot.txt
Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate;
GO:0006107 oxaloacetate metabolic process
ISS
GO_REF:0000024 		ACCEPT
Summary: Oxaloacetate metabolic process, transferred by sequence similarity.
Reason: Oxaloacetate is a direct substrate/product of the reaction.
Supporting Evidence:
file:DROME/Got2/Got2-uniprot.txt
Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate;
GO:0006520 amino acid metabolic process
IEA
GO_REF:0000002 		MODIFY
Summary: Amino acid metabolic process from InterPro.
Reason: Correct but a general process; MODIFY to L-aspartate biosynthetic process and L-glutamate biosynthetic process, both already annotated to Got2 (GO:0006532: ISS; GO:0097054: IDA, IMP).
Supporting Evidence:
file:DROME/Got2/Got2-uniprot.txt
DR InterPro; IPR000796; Asp_trans.
GO:0006532 L-aspartate biosynthetic process
ISS
GO_REF:0000024 		ACCEPT
Summary: L-aspartate biosynthetic process, transferred by sequence similarity.
Reason: Mitochondrial AST is the main source of aspartate, formed from oxaloacetate and glutamate in the matrix and exported for the malate-aspartate shuttle and biosynthesis.
Supporting Evidence:
file:DROME/Got2/Got2-uniprot.txt
Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate;
GO:0006533 L-aspartate catabolic process
IBA
GO_REF:0000033 		ACCEPT
Summary: L-aspartate catabolic process, phylogenetic inference.
Reason: Reversible transamination; aspartate can be deaminated to oxaloacetate. Acceptable family-level inference, though the mitochondrial isozyme mostly runs toward aspartate.
Supporting Evidence:
file:DROME/Got2/Got2-uniprot.txt
Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate;
GO:0006538 L-glutamate catabolic process
ISS
GO_REF:0000024 		ACCEPT
Summary: L-glutamate catabolic process, transferred by sequence similarity.
Reason: In mitochondria glutamate is transaminated with oxaloacetate to 2-oxoglutarate, feeding the TCA cycle; appropriate for the mitochondrial isozyme.
Supporting Evidence:
file:DROME/Got2/Got2-uniprot.txt
Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate;
GO:0007416 synapse assembly
IMP
PMID:11753421
Developmental regulation of glutamate receptor field size by... 		KEEP AS NON CORE
Summary: Synapse assembly, from GOT mutants altering glutamate receptor field size at the NMJ (Featherstone et al. 2002).
Reason: Featherstone et al. manipulated presynaptic glutamate levels genetically and found that glutamate negatively regulates postsynaptic receptor field size during synaptogenesis. Got2 acts indirectly here, by setting the glutamate pool rather than by building synapses; the curators read the full text, so the annotation is retained but as a non-core, downstream consequence of the enzyme's metabolic role.
Supporting Evidence:
PMID:11753421
Our data show that presynaptic glutamate is a strong negative regulator of postsynaptic receptor field size and function during development.
GO:0008483 transaminase activity
IEA
GO_REF:0000002 		MODIFY
Summary: Transaminase activity from InterPro.
Reason: Correct parent; MODIFY to L-aspartate:2-oxoglutarate transaminase activity, which Got2 already carries (IBA, IDA, IEA).
Supporting Evidence:
file:DROME/Got2/Got2-uniprot.txt
DR PROSITE; PS00105; AA_TRANSFER_CLASS_1; 1.
GO:0030170 pyridoxal phosphate binding
IEA
GO_REF:0000002 		ACCEPT
Summary: Pyridoxal phosphate binding from InterPro.
Reason: AST is PLP-dependent. Got2 carries the PROSITE aminotransferase class-I pyridoxal-phosphate attachment site signature (PS00105; InterPro IPR004838) and the PLP-dependent transferase signature (IPR015424). The UniProt COFACTOR line is an ARBA prediction and is not cited.
Supporting Evidence:
file:DROME/Got2/Got2-uniprot.txt
DR InterPro; IPR004838; NHTrfase_class1_PyrdxlP-BS.
file:DROME/Got2/Got2-uniprot.txt
DR InterPro; IPR015424; PyrdxlP-dep_Trfase.
GO:0043490 malate-aspartate shuttle
ISS
GO_REF:0000024 		ACCEPT
Summary: Malate-aspartate shuttle, transferred by sequence similarity.
Reason: Mitochondrial AST is a core component of the malate-aspartate shuttle.
Supporting Evidence:
file:DROME/Got2/Got2-uniprot.txt
DR PANTHER; PTHR11879:SF22; ASPARTATE AMINOTRANSFERASE, MITOCHONDRIAL; 1.
GO:0097054 L-glutamate biosynthetic process
IDA
PMID:3106567
A genetic analysis of glutamatergic function in Drosophila. 		ACCEPT
Summary: L-glutamate biosynthetic process (Chase and Kankel 1987).
Reason: AST forms glutamate from 2-oxoglutarate; studied as a regulator of transmitter glutamate pools.
Supporting Evidence:
PMID:3106567
enzymatic activities thought to be important in the regulation of transmitter-glutamate pools
GO:0097054 L-glutamate biosynthetic process
IMP
PMID:11753421
Developmental regulation of glutamate receptor field size by... 		ACCEPT
Summary: L-glutamate biosynthetic process, from GOT mutants with altered glutamate (Featherstone et al. 2002).
Reason: The study manipulated presynaptic glutamate levels genetically; curators annotated Got2 from the full text. Consistent with the enzyme's role in glutamate supply.
Supporting Evidence:
PMID:11753421
we genetically manipulated presynaptic glutamate levels at the glutamatergic Drosophila neuromuscular junction (NMJ)

Core Functions

Got2 reversibly transaminates L-glutamate and oxaloacetate to 2-oxoglutarate and L-aspartate in the mitochondrial matrix, forming the mitochondrial arm of the malate-aspartate shuttle and a source of aspartate and glutamate.

Molecular Function:
L-aspartate:2-oxoglutarate transaminase activity
Directly Involved In:
malate-aspartate shuttle L-aspartate biosynthetic process L-glutamate biosynthetic process
Cellular Locations:
mitochondrion
Supporting Evidence:
  • PMID:823072
    The aspartate aminotransferases (designated GOT1 and GOT2) are two enzymes of Drosophila melanogaster

References

Loading supporting content…

Download this section (compressed HTML)

Suggested Questions for Experts

Q: Which AST isozyme (cytosolic Got1 or mitochondrial Got2) sets the presynaptic glutamate pool at the larval NMJ, and is the effect cell-autonomous in motor neurons?

Suggested Experiments

Experiment: Motor-neuron-specific Got2 knockdown with glutamate imaging (iGluSnFR) and receptor-field quantification to test whether Got2 controls nonvesicular glutamate release.

Deep Research

FlyBase

(Got2-deep-research-flybase.md)
FlyBase gene description for Got2 (DROME) FlyBase

FlyBase gene description for Got2 (DROME)

Glutamate oxaloacetate transaminase 2 (Got2) encodes a mitochondrial enzyme that catalyzes the interconversion of L-aspartate and alpha-ketoglutarate to oxaloacetate and L-glutamate. It is involved in glutamate and aspartate biosynthesis, gluconeogenesis and the malate-aspartate shuttle.

📚 Additional Documentation

Notes

(Got2-notes.md)

Loading supporting content…

Download this section (compressed HTML)

📄 View Raw YAML

Loading supporting content…

Download this section (compressed HTML)