4483
These findings are consistent with a model for Rex -mediated trans-activation in which Rex -viral mRNA complexes are targeted for nuclear export by the direct action of the activation domain .
 ( protein: Rex, None) , ( protein: Rex, None) , ( protein: activation domain, None) , ( protein: Rex -viral mRNA complexes, None) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: RNA,cell type,protein,cell line,DNA, Arguments type: . 
Text: {0} 
Answer:
 ( protein: Rex, None) , ( protein: Rex, None) , ( protein: activation domain, None) , ( protein: Rex -viral mRNA complexes, None) 