MYD88 Antibody

MYD88, myeloid differentiation primary response 88, was identified as an innate immune signal transduction adaptor involved in the Toll-like receptor (TLR) and interleukin-1 (IL-1) signaling pathway (1,2,3) and plays an important role in the inflammatory response induced by cytokines IL-1 and IL-18 and endotoxin. MyD88 functions as an adaptor protein for TLRs and IL-1 receptors, which stimulates IRAKs, IRF7 and TRAF6, leading to NF-κB activation, cytokine secretion and inflammatory response (2, 4,5,6) . Nuclear factor-kappa-B activation modulates multiple genes regulating the body's immune reactions and inflammatory responses. MyD88 associates with and recruits IRAK to the IL-1 receptor complex in response to IL-1 treatment and dominant negative form of MyD88 attenuates IL-1R-mediated NF-κB activation (4,5) . MyD88 is also employed as a regulator molecule by IL-18 receptor. Targeted disruption of the MyD88 gene results in loss of cellular responses to IL-1 and IL-18, and MyD88-deficient mice lack responses to bacterial product LPS that employs TLR2 and TLR4 as the signaling receptors (7,8) . MyD88 gene is expressed in many tissues.

Independent Antibody Validation in Cell lines (Figure 2) shows similar MYD88 expression profile in both human and mouse cell lines detected by two independent anti-MYD88 antibodies that recognize different epitopes, 2125 against internal domain and 2127 against the C-terminus domain. MYD88 proteins are detected in all the tested cell lines at different expression levels by the two independent antibodies. Additionally, Figure 2 shows the mouse MYD88 protein in NIH/3T3 cells migrates slightly faster than human isoform 1 detected by both MYD88 antibodies (2125 and 2127), which is well correlated with their calculated molecular masses (33.8 kDa vs 35.4 kDa) . Independent Antibody Validation in Cell lines2125 2127 Independent Antibody Validation in Human Tissues (Figure 3) shows similar MYD88 expression profile in human tissues detected by two independent anti-MYD88 antibodies (2125 and 2127) . MYD88 proteins are detected by the two independent antibodies in liver, kidney, lung, thymus, colon, bladder and breast of human tissues at different expression levels, but not in heart, brain, skin and pancreas. Independent Antibody Validation in Human Tissues Animal Species Reactivity (Figure 4) : Anti-MYD88 antibodies (2125 and 2127) can detect the expression of MYD88 protein in the liver and spleen of all tissues and mouse heart, but not in human heart. Additionally, Figure 4 also shows MYD88 protein detected by both MYD88 antibodies (2125 and 2127) in human liver and Daudi cells migrates slightly slower than that in the tissues of mouse and rat, which is well correlated with their calculated molecular masses (35.4 kDa vs 33.8 kDa and 33.9kD) . Animal Species Reactivity21252127 siRNA knockdown validation (Figure 5) : Anti-MYD88 antibody (2125) specificity was further verified by MYD88 specific siRNA knockdown. MYD88 signal in HeLa cells transfected with MYD88 siRNAs was weaker in comparison with that in HeLa cells transfected with control siRNAs. siRNA knockdown validation2125

MYD88 antibody can be stored at 4˚ C for three months and -20˚ C, stable for up to one year. As with all antibodies care should be taken to avoid repeated freeze thaw cycles. Antibodies should not be exposed to prolonged high temperatures.

Human MYD88 has 7 isoforms, including isoform 1 (317aa, 35.4kD), isoform 2 (296aa, 33.2 kD), isoform 3 (251aa, 28.3kD), isoform 4 (191aa, 20.8kD), isoform 5 (146aa, 15.8kD), isoform 6 (275aa, 31.5kD), and isoform 7 (304aa, 34.1kD) . This antibody detects human isoform 1,2,3,6,7, but not isoform 4,5. Mouse MYD88 has two isoforms, including isoform 1 (296aa, 33.8kD) and isoform 2 (250aa, 28.7kD) . Rat MYD88 has only one isoform identified so far (296aa, 33.9kD) .