FYPP1 Antibody

Molecular Identity of FYPP1

FYPP1 (AT1G50370) encodes a serine/threonine protein phosphatase belonging to the PP2A family. It shares structural homology with human PP6 phosphatases and functions in a holoenzyme complex with regulatory subunits like RCN1 and SAL proteins . Key features include:

• Catalytic activity: Requires a conserved D81 residue for enzymatic function .

• Subcellular localization: Primarily plasma membrane-associated, influencing PIN protein polarity .

• Gene structure: Contains 12 exons; T-DNA insertions in introns or UTR regions disrupt its expression .

Research Applications of FYPP1 Antibody

The FYPP1 antibody has been instrumental in:

PIN Protein Localization Studies

FYPP1 regulates PIN1/PIN2 polarity by dephosphoryating auxin transporters. Immunostaining using FYPP1 antibody revealed:

Mutants (fypp1-1, fypp1-2) show apical shift in PIN localization, rescued by 35S::FYPP1 transgenes .

Phosphorylation-Dependent Signaling

FYPP1 antagonizes PID kinase to control PIN1 distribution:

• PID overexpression: Reduces lobe-localized PIN1 to 30% .

• FYPP1 loss-of-function: Increases non-polar PIN1 to 89% .

Genetic Interactions

• Double mutants (f1 f3) exhibit synergistic defects in hypocotyl elongation and photomorphogenesis .

• PP6 holoenzyme: FYPP1 forms a 440 kDa complex with RCN1 and SAL1, confirmed by coimmunoprecipitation .

Phenotypic Rescue

• 35S::FYPP1 restores wild-type PIN localization and leaf pavement cell (PC) patterning in mutants .

• Catalytic dead mutants (D81N-FYPP1) fail to complement fypp1, confirming phosphatase activity is essential .

Technical Validation

• Specificity: The antibody detects FYPP1 in Western blots and immunolocalization assays, with no cross-reactivity to PP2Ac4 .

• Functional assays: Used in gel filtration and yeast three-hybrid systems to map protein interactions .

Research Implications

FYPP1 antibody studies have clarified:

• Auxin transport regulation: FYPP1-mediated dephosphorylation directs PIN polarity, impacting leaf morphogenesis .

• Light signaling: FYPP1-PP6 complexes modulate PIF transcription factors to repress photomorphogenesis .