AGP21 Antibody

AGP21 Function and Detection Methods

AGP21 is a Hyp-O-glycosylated peptide critical for regulating root hair (RH) cell patterning. Key findings include:

• Role in RH Development: Loss of AGP21 (agp21 mutants) results in ectopic contiguous RH formation due to disrupted BR signaling .

• O-Glycosylation Dependency: Mutation of AGP21’s three proline residues (Pro→Ala) abolishes its function, confirming that Hyp-O-glycans are essential for its activity .

• BR Signaling Interaction: AGP21 localizes near BRI1–BAK1 receptors at the plasma membrane, suggesting it modulates BR perception .

Table 1: AGP21 Functional Studies

Antibody-Based Detection of AGP21

While no study explicitly describes an AGP21-specific antibody, AGP21 has been studied using:

• Venus/GFP Fusion Constructs: Transgenic lines (e.g., AGP21p::Venus-AGP21) enable visualization via fluorescent tags .

• General AGP Antibodies: Monoclonal antibodies like JIM8 and JIM13, which recognize arabinogalactan epitopes, label AGP21 in reproductive tissues .

Table 2: AGP Detection Tools

AGP21 in Developmental Mutants

AGP21 expression varies in Arabidopsis mutants affecting reproductive development:

• qPCR Data:

  • stk mutants show upregulated AGP21 expression.

  • ntt stk double mutants exhibit altered AGP21 distribution in ovules .

Table 3: AGP21 Expression in Mutants

Technical Challenges and Future Directions

• Antibody Specificity: No AGP21-specific antibody exists; current methods rely on epitope tags or broad-spectrum AGP antibodies.

• Functional Studies: AGP21’s interaction with BR receptors remains indirect; advanced techniques (e.g., FRET or cryo-EM) could clarify its role .

• Biomedical Context: While unrelated to AGP21, anti-gp210 antibodies (targeting nuclear envelope glycoprotein 210) are biomarkers for primary biliary cholangitis .