FIGURE 4.
Associative competition among putative tripartite LINGO-1·p75NTR·NgR receptor members. p75NTR immunoprecipitation (IP) in the presence of increasing LINGO-1-V5 expression reduced the amount of co-immunoprecipitated NgR in a LINGO-1 dose-dependent manner. Epitope-tagged LINGO-1, p75NTR, and NgR were expressed in transfected HEK293 cells. Cell extracts and immunoprecipitates made using antibody against the epitope tag of p75NTR were assessed by immunoblot (IB) analysis using antibodies against the epitope tags of each protein. All lanes depicted derived from the same gel. For the anti-FLAG immunoblot of immunoprecipitates of FLAG-NgR, the prominent lower 50-kDa band is an artifact, representing the heavy chain of IgG. The band running slightly above the 50-kDa position represents FLAG-NgR. The first band in the last whole cell lysate (WCL) image (anti-FLAG) is partially obscured due to uneven blot transfer; NgR expression in this lane can be inferred by the strong co-immunoprecipitation of NgR via p75NTR-Myc as seen in the upper blot.