XBP1 Rabbit Polyclonal Antibody for WB, IF/ICC, ELISA - P17861

Core Product Specifications and Parameters

Biological Background: XBP1 Function and Localization

• XBP1 exists as two main isoforms: the unspliced form (XBP1u) acts as a weak transcription factor and primarily regulates the unfolded protein response (UPR) through negative feedback, while the spliced form (XBP1s) is a potent transcriptional activator of UPR target genes. Related references: PMID:8657566 PMID:16461360 PMID:11779464 PMID:25239945
• XBP1 is central to the unfolded protein response (UPR), binding to ER stress response element (ERSE) and UPR element (UPRE) to upregulate ER chaperones and ER-associated degradation components. Related references: PMID:11779464 PMID:25239945
• The production of active XBP1s involves unconventional cytoplasmic splicing of XBP1 mRNA by the endoribonuclease IRE1α (ERN1) upon ER stress. Related references: PMID:19394296 PMID:21233347 PMID:23529610
• XBP1u provides negative feedback by targeting XBP1s for proteasome-mediated degradation, preventing hyperactivation of the UPR. Related references: PMID:16461360 PMID:25239945
• XBP1 localizes to the endoplasmic reticulum membrane and shuttles to the nucleus upon activation, with additional presence in the cytoplasm.
• In immune cells, XBP1 is essential for plasma cell differentiation and immunoglobulin production, and is expressed in rheumatoid synovium. Related references: PMID:11460154
• XBP1 contributes to cancer progression: overexpression in breast cancer promotes epithelial-mesenchymal transition (EMT) and metastasis via SNAI1 upregulation. Related references: PMID:25280941
• In endothelial cells, XBP1 promotes VEGF-induced angiogenesis and proliferation, and regulates autophagy through BECN1 transcriptional activation. Related references: PMID:23529610 PMID:23184933 PMID:19416856

Experimental Guidance and Technical Tips

• Based on the immunogen design (recombinant protein/synthetic peptide corresponding to a.a. 277–376 of human XBP1), the antibody may recognize both unspliced (~29 kDa) and spliced (~55 kDa) isoforms; validation with specific isoform controls or ER stress induction (e.g., tunicamycin) is recommended.
• For Western blot (WB) using this rabbit polyclonal antibody, separate proteins under reducing conditions and expect a band near 29 kDa for XBP1u; induction of ER stress can shift signal to the larger spliced form.
• In immunofluorescence (IF/ICC), optimize fixation (e.g., 4% PFA) and permeabilization (e.g., 0.1% Triton X-100) to retain ER/nuclear localization; co-stain with organelle markers to confirm subcellular distribution.
• For ELISA, consider using the antibody as a capture or detection reagent against recombinant XBP1 protein or cell lysates; titration and blocking conditions should be optimized per assay.
• Cross-reactivity with mouse and rat is reported; however, sequence homology within the immunogen region should be verified for your specific experimental model.

CamelBio: Your One-Stop Sourcing Bridge

CamelBio specializes in providing diagnostic manufacturers, labs, and research institutes with a comprehensive range of IVD raw materials. For targets like XBP1 involved in ER stress and cancer biology, we can supply validated antibody pairs, optimized recombinant proteins, and bulk ancillary reagents to support your diagnostic and research workflows. Our one-stop sourcing model also extends to rare target raw-material procurement, ensuring you have the critical components for assay development.