7240
These complexes are coordinately expressed except during replicative senescence , which is characterized by the down-modulation of site beta -but not site alpha -binding activities .
 ( protein: site alpha, None) , ( protein: site beta, 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: site alpha, None) , ( protein: site beta, None) 