6648
N-formyl-methionyl-leucyl-phenylalanine ( FMLP ) and phorbol myristate acetate ( PMA ) induced tyrosine phosphorylation of 42- and 44- kDa proteins , which were identified as extracellular signal-regulated kinase ( ERK ), in human monocytes .
 ( protein: ERK, None) , ( cell type: human monocytes, None) , ( protein: extracellular signal-regulated kinase, 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: ERK, None) , ( cell type: human monocytes, None) , ( protein: extracellular signal-regulated kinase, None) 