rpa-1 Antibody

Definition and Structure of RPA1 Antibody

RPA1 is a single-stranded DNA (ssDNA)-binding protein essential for DNA metabolism. The RPA1 antibody detects this protein across species, including humans and mice, with high specificity . Structurally, RPA1 comprises 616 amino acids (68 kDa predicted, 70 kDa observed) . Commercial antibodies (e.g., Proteintech 12448-1-AP, Cell Signaling Technology #2267) are typically rabbit or mouse-derived polyclonal/monoclonal antibodies validated for techniques like Western blot (WB), immunoprecipitation (IP), and immunofluorescence (IF) .

Applications in Research

RPA1 antibodies are widely used to investigate DNA damage response and immune cell regulation. Key applications include:

Table 1: Common Applications of RPA1 Antibodies

Role in T Cell Homeostasis and Autoimmunity

• T Cell Necroptosis: RPA1 deletion in T cells triggers genomic DNA leakage, activating ZBP1-RIPK3 signaling and necroptosis, leading to lymphopenia and aggravated colitis/hepatitis in mice .

• Clinical Correlation: Reduced RPA1 levels are observed in ulcerative colitis patients, suggesting its role as a biomarker for autoimmune diseases .

Cancer Research Insights

• Breast Cancer: RPA1 expression is significantly downregulated in ductal carcinoma in situ (DCIS) and invasive breast cancers, correlating with higher recurrence risk .

• Liver Cancer: RPA1-ETAA1 axis dysregulation in hepatocellular carcinoma (LIHC) is linked to PD-L1 expression and poor prognosis .

DNA Repair Mechanisms

RPA1 stabilizes ssDNA during replication stress, facilitating recruitment of repair proteins (e.g., RAD51, XPA) and checkpoint activation (ATR/CHK1) .

Technical Considerations

• Dilution Optimization: Titration is critical for assays like WB, where background noise varies by cell type .

• Storage: Stable at -20°C in PBS with 0.02% sodium azide .

• Cross-Reactivity: Most antibodies target human and mouse RPA1, but validation in non-model systems is advised .

Future Directions

Current research explores RPA1’s dual role in genome stability and immune regulation. Targeting the RPA1-ZBP1 axis may offer therapeutic strategies for autoimmune diseases, while its downregulation in cancers highlights potential diagnostic utility .