173
Our results suggest that SP1 phosphorylation induced by OKA , a selective inhibitor of the serine-threonine phosphatase PP2A , facilitates the formation of a transcription complex involving general transcription factors , HIV Tat , and Sp1 proteins .
 ( protein: Sp1, None) , ( protein: transcription factors, None) , ( protein: PP2A, None) , ( protein: HIV Tat, None) , ( protein: serine-threonine phosphatase, None) , ( protein: Sp1 proteins, None) , ( protein: SP1, None) , ( protein: transcription complex, 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: Sp1, None) , ( protein: transcription factors, None) , ( protein: PP2A, None) , ( protein: HIV Tat, None) , ( protein: serine-threonine phosphatase, None) , ( protein: Sp1 proteins, None) , ( protein: SP1, None) , ( protein: transcription complex, None) 