5289
G protein coupled - receptor ( GPCR ) kinases ( GRKs ) initiate the deactivation of GPCRs by phosphorylating their cytoplasmic loops and C - terminal tails .
 Chemical: C
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: C