Affiliation:
1. Division of Microbiology, National Institute of Health Sciences, Setagaya, Tokyo 158-8501, Japan
Abstract
ABSTRACT
MD-2 has been reported to be required for the translocation of the Toll-like receptor 4 (TLR4) to the cell surface. However, the mechanism by which MD-2 promotes TLR4 translocation is unknown. We identified the presence of two forms of TLR4 with different molecular masses (approximately 110 and 130 kDa) when TLR4 was expressed together with MD-2. Expressing TLR4 alone produced only the 110-kDa form. Using a membrane-impermeable biotinylation reagent, we found that only the 130-kDa form of TLR4 was expressed on the cell surface. When a cellular extract prepared from cells expressing TLR4 and MD-2 was treated with
N
-glycosidase, the two forms of TLR4 converged into a single band whose size was smaller than the 110-kDa form of TLR4. Mutation of TLR4 at Asn
526
or Asn
575
resulted in the disappearance of the 130-kDa form and prevented TLR4 from being expressed on the cell surface without affecting the ability of TLR4 to associate with MD-2. These results indicate that TLR4 is able to undergo multiple glycosylations without MD-2 but that the specific glycosylation essential for cell surface expression requires the presence of MD-2.
Publisher
American Society for Microbiology
Subject
Microbiology (medical),Clinical Biochemistry,Immunology,Immunology and Allergy
Cited by
79 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献