The expression of syntaxin 4 and co-interaction with SNAP-23 in human NK cells
Objective To study the expression of syntaxin 4 and interaction with other related proteins in human NK cells and to create a new idea to interfere the exocytosis in NK cytotoxin process. Method We examined the syntaxin 4 gene by RT PCR, the protein expression of syntaxin 4 in resting and activated NK cells by Western blot, the relocation of syntaxin 4 in resting and activated NK cells by indirect immunofluorescence and the interaction with SNAP 23 by coimmunoprecipitation. Results Syntaxin 4 is expressed both at mRNA and protein level. It is primarily located in cytomembrane dispersively and concentrated as a cap after stimulation by PEC. Coimmunoprecipitation assays indicated that syntaxin 4 interacts with SNAP 23 in vivo . Conclusion Syntaxin 4 is concerned with the recognition of target cell in transplantation rejection and interacts with the signal transmitter, SNAP 23. So, it may act as a target molecule in the regulation of exocytosis in NK cytotoxicity.