Alpha-adducin (ADD1) is a cytoskeletal protein that caps actin filaments and recruits spectrin to stabilize membrane-cytoskeleton interactions . Phosphorylation at Ser726 occurs in the C-terminal MARCKS domain, regulating ADD1’s actin-capping activity and interaction with signaling molecules like PKC-θ .
Functional Impact: Phosphorylation inhibits actin-capping, enabling dynamic cytoskeletal remodeling during T-cell immune synapse formation .
Kinase Involvement: PKC family kinases phosphorylate Ser726, peaking 2–5 minutes post-TCR activation .
Biological Relevance: Linked to CD28 costimulation and IL-2 production in CD4+ T cells .
Phospho-ADD1 (Ser726) Antibody is a rabbit polyclonal antibody generated using synthetic phosphopeptides (sequence: T-P-S(p)-F-L) conjugated to KLH .
Negative Controls: Pre-absorption with immunizing phosphopeptide abolishes signal .
CD28 Costimulation: Add1-deficient CD4+ T cells show defective proliferation and CD25 upregulation under suboptimal TCR stimulation, highlighting ADD1’s role in costimulatory signaling .
Immune Synapse Dynamics: Phospho-ADD1 localizes peripherally at the immune synapse, colocalizing with F-actin distal to TCR clusters .
Kinetic Regulation: Ser726 phosphorylation peaks within minutes of TCR engagement, correlating with PKC-θ activation .
Hypertension: ADD1 polymorphisms are linked to essential hypertension .
Cancer: Aberrant ADD1 phosphorylation is observed in breast cancer tissues .
PMC6879651 (2019): First demonstration of ADD1’s role in CD28 costimulation and immune synapse dynamics .
SAB (2025): Technical validation of antibody specificity using peptide inhibition .
Elabscience (2025): Confirmed reactivity in HeLa cells and human breast cancer tissues .
Mechanistic Studies: Elucidate how Ser726 phosphorylation modulates spectrin-actin interactions in non-immune cells.
Therapeutic Potential: Target ADD1 phosphorylation pathways in autoimmune diseases or cancers with cytoskeletal dysregulation.