Figure 6. Cell surface p75^NTR dimerization is mediated by covalent and non-covalent interactions between transmembrane domains.

(A) Wild type and C257A p75^NTR dimers analyzed by cell surface chemical crosslinking under reducing conditions. Cell lysates were immunoprecipitated with anti-p75^NTR antibodies; immunoblot was probed with anti-HA antibodies.

(B) Alignment of p75^NTR transmembrane domains highlighting the AxxxG self-association motif and Gly²⁶⁶.

(C) ToxCAT assay of self-association of wild type and mutant p75^NTR transmembrane domains. Wild type and mutant transmembrane domains from glycophorin A (GpATM) were used as positive and negative controls, respectively.

(D) Wild type and mutant p75^NTR dimers analyzed by cell surface chemical crosslinking as above.