TLR4-DN-HA

Expression-ready ORF Clones

Alias: TLR4, CD284

HA-Tagged TLR4-DN (ΔTIR): Dominant Negative TIR-less TLR4 gene

TLR4 is the receptor for Gram- lipopolysaccharide (LPS). The TLR4 gene was shown to be mutated in C3H/HeJ and C57BL/10ScCr mice, both of which are low responders to lipopolysaccharide (LPS) [1].
However, TLR4 alone is not sufficient to confer LPS responsiveness. TLR4 requires MD-2, a secreted molecule, to functionaly interact with LPS [2].
Furthermore, a third protein, called CD14, was shown to participates in LPS signaling, leading to NF-κB translocation. This signaling is mediated through the adaptor protein MyD88 but also through a MyD88-independent pathways that involves the (TIR) domain-containing adapter protein (TIRAP) [3].
TLR4-DN is a TIR-less form of the TLR4 gene generated by deleting the TIR domain (498 bp); This truncated gene is still able to recognize its ligands but is unable to induce the signaling cascade. The gene has been fused at the 3'end to the influenza hemagglutinin (HA) tag. This short sequence (YPYDVPDYA) encodes a peptide which is the epitope of a very efficient and specific monoclonal antibody. The use of HA-tagged genes provides a simple and convenient method to detect the expression of the genes by Western blot.

References

1. Poltorak A. et al., 1998. Science, 282(5396):2085-8.
2. Shimazu R. et al., 1999. J Exp Med, 189(11):1777-82.
3. Horng T. et al., 2001. Nat Immunol, 2(9):835-41.