SCAMP4 Antibody

Definition and Biological Context

SCAMP4 antibodies are immunological reagents designed to detect and quantify SCAMP4, a membrane protein implicated in regulating the senescence-associated secretory phenotype (SASP). SCAMP4 is part of the SCAMP family but lacks N-terminal NPF repeats found in other members, distinguishing its role in secretory processes over endocytosis . It is upregulated in senescent cells and enhances the secretion of SASP factors like IL-6, IL-8, and GDF-15, contributing to age-related pathologies .

Target Protein Characteristics

• Molecular Weight: ~25 kDa .

• Domains: Four transmembrane regions and a short cytoplasmic tail .

• Post-Translational Modifications: Ubiquitinated at Lys4 and Lys185 in proliferating cells, leading to proteasomal degradation .

Epitope Information

Commercial SCAMP4 antibodies commonly target synthetic peptides or recombinant fragments, such as:

• Immunogen Sequence: KVHRIYRGAGGSFQKAQTEWNTGTWRNPPSREAQYNNFSGNSLPEYPTVPSYPGSGQWP .

• Cross-Reactivity: 85% identity with mouse SCAMP4 and 87% with rat .

Role in Cellular Senescence

• SCAMP4 Upregulation: Surface levels increase >5-fold in senescent human fibroblasts (WI-38, IMR-90) and endothelial cells (HAECs, HUVECs) .

• SASP Regulation:

  • Silencing SCAMP4 reduces secretion of IL-6 (↓42%), IL-8 (↓38%), and GDF-15 (↓55%) in senescent cells .

  • Overexpression in proliferating cells elevates SASP factors (IL-6 ↑2.3-fold, IL-8 ↑1.9-fold) and induces senescence markers (p16, p53) .

Mechanistic Studies

• Ubiquitination: SCAMP4 is degraded via the ubiquitin-proteasome system (UPS) in proliferating cells but stabilizes in senescent cells .

• Autocrine Effects: SCAMP4-driven SASP factors reinforce senescence locally via NF-κB and C/EBPβ signaling .

Western Blot Performance

Immunohistochemistry (IHC)

• Thermo Fisher PA5-60309: Localizes SCAMP4 to the plasma membrane in non-permeabilized senescent cells .

• Sigma-Aldrich HPA043284: Staining correlates with RNA-seq data in Human Protein Atlas .

Implications for Aging and Disease

SCAMP4 antibodies have enabled critical discoveries in aging research:

• Therapeutic Targeting: SCAMP4 inhibition reduces SASP-driven pathologies (e.g., atherosclerosis, fibrosis) .

• Biomarker Potential: Elevated SCAMP4 in senescent cells links to neurodegenerative disorders and cancer progression .