+MOD_ATT+SUBJ:V-N+-OBJ:V-N-+COMP:N-N(of)+     
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 __NODE__ protein mediates activation of __NODE__ .
MOD_ATT:N-ADJ (protein,__NODE__)
SUBJ:V-N (mediate,protein)
OBJ:V-N (mediate,activation)
COMP:N-N(of) (activation,__NODE__)