Homophilic interactions mediated by receptor tyrosine phosphatases mu and kappa. A critical role for the novel extracellular MAM domain

摘要: The receptor-like protein tyrosine phosphatases (RPTP) mu and RPTP kappa have a modular ectodomain consisting of four fibronectin type III-like repeats, single Ig-like domain, newly identified N-terminal MAM domain. function the latter module, which comprises about 160 amino acids is found in diverse transmembrane proteins, not known. We previously reported that both can mediate homophilic cell interactions when expressed insect cells. Here we show despite their striking structural similarity, fail to interact heterophilic manner. To examine role domain binding, mutant lacking Sf9 Truncated properly at surface but fails promote cell-cell adhesion. Homophilic adhesion fully restored chimeric molecule containing kappa. However, this does with either or These results indicate essential for interaction helps determine specificity these interactions.