VTC2 Antibody
Description
Definition and Applications of VTC2 Antibody
The VTC2 antibody is a specialized immunological reagent targeting GDP-L-galactose phosphorylase (VTC2), a critical enzyme in ascorbic acid (vitamin C) biosynthesis pathways . This antibody enables researchers to detect, quantify, and study the spatial distribution of VTC2 in plant tissues through techniques such as:
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Western blotting
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ELISA
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Immunohistochemistry
Key technical specifications (from PhytoAB ):
| Property | Details |
|---|---|
| Reactivities | Arabidopsis thaliana, Brassica napus, Solanum lycopersicum, etc. |
| Storage | Lyophilized; avoid repeated freeze-thaw cycles |
| Cross-reactivity | Confirmed in Vitis vinifera, Nicotiana tabacum, and other species |
Biological Role of VTC2 in Cellular Processes
VTC2 functions as part of the vacuolar transporter chaperone (VTC) complex, which regulates polyphosphate (polyP) synthesis and vacuolar membrane dynamics . Its roles include:
Regulation of Polyphosphate Metabolism
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The VTC complex exists in two isoforms: Vtc1/2/4 and Vtc1/3/4, with Vtc2 acting as a regulatory subunit .
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Vtc2 binds inositol pyrophosphates via its SPX domain, triggering conformational changes that activate polyP synthesis from ATP .
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Knockout studies show compensatory polyP production by alternate VTC isoforms (e.g., vtc2 mutants exhibit upregulated Vtc3 activity) .
Ascorbate Biosynthesis
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VTC2 catalyzes the transfer of GMP from GDP-galactose to hexose-1-phosphate, a rate-limiting step in ascorbate synthesis .
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Mutants (vtc2) display altered expression of defense-related genes (e.g., PR1, WRKY53) and transcription factors linked to stress responses :
Gene expression changes in vtc2 mutants :
| Gene ID | Fold Change | Function |
|---|---|---|
| At4g23810 | +5.96 | WRKY53 transcription factor (defense) |
| At2g17040 | +3.91 | NAC036 (stress signaling) |
| At1g27730 | +3.83 | ZAT10 (salt tolerance) |
Research Implications and Applications
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Stress Response Studies: The antibody aids in tracking VTC2’s role during oxidative stress, as ascorbate deficiency in vtc2 mutants correlates with upregulated defense genes .
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Polyphosphate Dynamics: VTC2-specific antibodies help dissect isoform-specific contributions to polyP storage, critical for phosphate homeostasis .
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Agricultural Biotechnology: Engineered vtc2 lines with modified ascorbate levels are studied for improved crop resilience .
Validation and Quality Control
Product Specs
Constituents: 50% Glycerol, 0.01M PBS, pH 7.4
Target Background
- GGP/VTC2 plays a crucial role as a rate-limiting step in regulating AsA biosynthesis in response to variations in light and dark conditions. PMID: 25036484
- The VTC5 promoter exhibits higher activity in young cotyledons. Notably, the VTC2 and VTC5 promoters, responsible for two GDP-L-galactose phosphorylase isozymes, drive a distinct day-to-night variation in expression. PMID: 21897033
- A significant proportion of primary roots in vtc2 plants cultivated on soil exhibited deviations from the wild-type responses to gravity. PMID: 16720601
- VTC2 from A. thaliana demonstrates a specific GDP-L-galactose/GDP-D-glucose phosphorylase activity. PMID: 17462988
- At4g26850 encodes GDP-L-galactose-hexose-1-phosphate guanyltransferase, responsible for catalyzing the transfer of GMP from GDP-L-galactose to a hexose-1-P, most likely D-mannose-1-phosphate in vivo. [galactose guanyltransferase] PMID: 17485667
- Research indicates that a GDP-L-galactose phosphorylase, encoded by the Arabidopsis thaliana VTC2 gene, catalyzes this specific step in the ascorbate biosynthetic pathway. PMID: 17877701
- Arabidopsis VTC2 and VTC5 proteins function as enzymes that guanylylate a conserved active site His residue with GDP-L-galactose, producing L-galactose 1-phosphate essential for vitamin C synthesis. Subsequently, they regenerate the enzyme using phosphate to form GDP. PMID: 18463094
- The VTC2 gene exhibits expression throughout all developmental stages, with higher mRNA levels observed in green tissues compared to the root. PMID: 18516687
