USP18 Rabbit Polyclonal Antibody for WB, IHC-P, IF/ICC, ELISA - Q9UMW8

Core Product Specifications and Parameters

Biological Background: USP18 Function and Localization

• USP18 is an interferon-induced ISG15-specific protease, also designated as UBP43, Ubl carboxyl-terminal hydrolase 18, ISG15-specific-processing protease, or Ubl thioesterase 18.
• As the major deISGylating enzyme, USP18 efficiently cleaves ISG15 conjugates linked via isopeptide bonds, thereby maintaining cellular ISGylation homeostasis. Related references: PMID:11788588
• In T cells, USP18 negatively regulates NF-kB, NFAT, and JNK signaling by deubiquitinating TAK1, which restricts IL-2 production and Th17 cell differentiation. Related references: PMID:23825189
• USP18 partners with USP20 to deubiquitinate STING1, a critical step that potentiates the innate antiviral immune response. Related references: PMID:27801882
• Through its recruitment by STAT2 to IFNAR2, USP18 interferes with the assembly of the interferon/IFNAR1/IFNAR2 ternary complex, serving as a negative feedback regulator of type I IFN signaling. Related references: PMID:28165510
• USP18 also attenuates type I interferon–driven inflammatory responses, highlighting its dual role in antiviral immunity and immune homeostasis. Related references: PMID:27325888 PMID:28165510
• An N-terminally truncated isoform acts as the primary deISGylase for nuclear proteins, safeguarding ISGylation balance within the nucleus. Related references: PMID:22170061
• The protein is distributed in both the cytoplasm and the nucleus and features a predicted molecular weight of approximately 43 kDa; it is classified as a thiol protease of the ubiquitin-like conjugation pathway.

Experimental Guidance and Technical Tips

• The immunogen is a synthetic peptide spanning amino acids 1–100 of human USP18; verify sequence homology when assessing cross‑reactivity with mouse and rat homologs.
• For western blotting (WB), expect a band near 43 kDa and include appropriate positive and negative controls to confirm antibody specificity.
• This polyclonal antibody is suitable for ELISA-based detection of USP18 or its deISGylation activity; consider using recombinant protein or cell lysate standards.
• For immunofluorescence (IF/ICC) and immunohistochemistry (IHC‑P), test antigen retrieval conditions and optimize primary antibody dilution in the tissue or cell type of interest.

CamelBio: Your One-Stop Sourcing Bridge

CamelBio partners with diagnostic developers and research laboratories to supply a full spectrum of IVD raw materials, from validated antibody pairs and optimized polyclonal antibodies to bulk ancillary reagents. This anti-USP18 product, targeting a key regulator of interferon signaling and immune responses, exemplifies our capability to source both common and rare-target reagents. Whether you require off‑the‑shelf antibodies or tailored raw‑material solutions, CamelBio bridges the gap from concept to clinical application.