SHISA9 Antibody

SHISA9 Antibody Overview

SHISA9 (also known as CKAMP44) is a brain-specific, type-I transmembrane protein that modulates AMPA receptor kinetics and synaptic plasticity . Antibodies targeting SHISA9 enable researchers to investigate its interactions, expression patterns, and functional roles in neuronal signaling.

Interaction with Scaffolding Proteins

SHISA9 binds PDZ domain-containing proteins via its C-terminal EVTV motif, including:

• PSD95/PSD93: Validated via co-immunoprecipitation (co-IP) in HEK293T cells and native brain tissue .

• GRIP1, PICK1, Lin7b: Confirmed in yeast two-hybrid and co-IP assays .
  Disruption of these interactions (e.g., using TAT-Shisa9 mimetic peptides) accelerates AMPA receptor deactivation and alters synaptic short-term plasticity .

Role in Synaptic Function

• SHISA9 slows AMPA receptor desensitization and recovery kinetics, influencing paired-pulse facilitation in hippocampal neurons .

• Blocking SHISA9-PSD95 interactions narrows hippocampal network oscillation frequencies, suggesting a role in synchronizing neuronal activity .

Validation and Specificity

• Western Blot: Detects a single band at ~68 kDa in rat brain lysates .

• Immunohistochemistry: Localizes SHISA9 to postsynaptic densities in human and mouse brain sections .

• Cross-Reactivity: No cross-reactivity with other GLIPR family proteins .

Functional Insights from Antibody-Based Studies

• SHISA9 stabilizes AMPA receptors at synapses by anchoring them to PSD95 scaffolds .

• Its C-terminal interactions are critical for tuning receptor kinetics and synaptic plasticity .

• Antibody-blocking experiments reveal SHISA9’s role in maintaining hippocampal network oscillations .

Technical Considerations

• Storage: Stable at 4°C short-term; long-term storage at -20°C .

• Blocking Peptides: Available for competition assays to confirm antibody specificity .