| Autor: |
Junko Iijima, Satoshi Kobayashi, Shinobu Kitazume, Yasuhiko Kizuka, Reiko Fujinawa, Hiroaki Korekane, Takuma Shibata, Shin-Ichiroh Saitoh, Sachiko Akashi-Takamura, Kensuke Miyake, Eiji Miyoshi, Naoyuki Taniguchi |
| Předmět: |
|
| Zdroj: |
Glycobiology; Nov2017, Vol. 27 Issue 11, p1006-1015, 10p |
| Abstrakt: |
Core fucosylation, a posttranslational modification of N-glycans, modifies several growth factor receptors and impacts on their ligand binding affinity. Core-fucose-deficient mice generated by ablating the α1,6 fucosyltransferase enzyme, Fut8, exhibit severe pulmonary emphysema, partly due to impaired macrophage function, similar to aged Toll-like receptor 4 (Tlr4)-deficient mice. We therefore suspect that a lack of core fucose affects the TLR4-dependent signaling pathway. Indeed, upon lipopolysaccharide stimulation, Fut8-deficient mouse embryonic fibroblasts (MEFs) produced similar levels of interleukin-6 but markedly reduced levels of interferon-β (IFN-β) compared with wild-type MEFs. Lectin blot analysis of the TLR4 signaling complex revealed that core fucosylation was specifically found on CD14. Even though similar levels of TLR4/myeloid differentiation factor 2 (MD2) activation and dimerization were observed in Fut8-deficient cells after lipopolysaccharide stimulation, internalization of TLR4 and CD14 was significantly impaired. Given that internalized TLR4/MD2 induces IFN-β production, impaired IFN-β production in Fut8-deficient cells is ascribed to impaired TLR4/MD2 internalization. These data show for the first time that glycosylation critically regulates TLR4 signaling. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
