Anti-Phospho-POLR2A CTD-S5 Rabbit Polyclonal Antibody for WB, IHC-P, ELISA - P24928

Core Product Specifications and Parameters

Biological Background: POLR2A (RPB1) Function and Localization

• As the largest subunit of RNA polymerase II, POLR2A/RPB1 forms the catalytic core responsible for DNA-dependent RNA synthesis, transcribing mRNA precursors and non-coding RNAs (PubMed:23748380, PubMed:27193682, PubMed:30190596). Related references: PMID:23748380 PMID:27193682 PMID:30190596

• Together with subunit POLR2B/RPB2, it forms the active center featuring a Mg2+-coordinating DxDGD motif and provides 3'→5' exonuclease proofreading to ensure transcriptional fidelity (PubMed:30190596, PubMed:8381534, PubMed:9852112). Related references: PMID:30190596 PMID:8381534 PMID:9852112

• The C-terminal domain (CTD) consists of 52 tandem heptapeptide repeats (YSPTSPS) and undergoes dynamic phosphorylation: Ser5 phosphorylation (target of this antibody) promotes promoter escape, while Ser2 phosphorylation facilitates elongation and mRNA processing (PubMed:24207025, PubMed:26124092). Related references: PMID:24207025 PMID:26124092

• Beyond its DNA-dependent role, POLR2A exhibits RNA-dependent RNA polymerase activity, contributing to non-coding RNA metabolism and acting as a replicase for hepatitis delta virus.

• Primarily localized to the nucleus, POLR2A also shuttles to the cytoplasm and associates with mitotic chromosomes, reflecting its multifaceted regulatory roles.

• Mutations in POLR2A are linked to neurodevelopmental disorder with hypotonia, intellectual disability, and characteristic facial features (NEDHIB), underscoring its essential role in human development.

• Post-translational modifications of the CTD, including acetylation and methylation of lysine residues, provide an additional regulatory layer for gene expression, with acetylation being crucial for immediate early gene activation.

Experimental Guidance and Technical Tips

• The immunogen is a synthetic peptide designed to specifically recognize the phosphorylated Ser5 residue within the CTD repeat context; cross-reactivity with non-phosphorylated peptide or other phospho-epitopes (e.g., Ser2, Ser7) should be assessed in the relevant sample system.
• For Western blot (WB) analysis, a major band at ~217 kDa corresponding to full-length POLR2A is expected; include phosphatase inhibitors in lysis and electrophoresis buffers to preserve the phospho-epitope.
• In immunohistochemistry (IHC-P), antigen retrieval methods may affect phospho-epitope stability; test mild citrate or EDTA-based protocols and validate with appropriate positive and negative phosphorylated controls.
• ELISA applications may require coating with phosphorylated peptide and blocking under conditions that maintain antibody specificity for the phospho-antigen.
• Cross-reactivity is reported for human, mouse, and rat samples; however, since the CTD repeat sequence is highly conserved, verify specificity in your specific model organism through sequence alignment if needed.

CamelBio: Your One-Stop Sourcing Bridge

CamelBio serves as a trusted one-stop partner for IVD raw-material procurement, supporting diagnostic manufacturers, research laboratories, and institutes from initial concept through clinical readiness. The phospho-POLR2A CTD-S5 antibody is part of our growing portfolio for transcriptional regulation and epigenetics research, complemented by validated antibody pairs, optimized monoclonal and polyclonal antibodies, bulk ancillary reagents, and rare target custom sourcing. Contact us to discuss your specific needs and explore how our integrated supply chain can streamline your development pipeline.