6870
The location of multiple GRK2 and GRK5 phosphoacceptor sites at the extreme carboxyl terminus of the beta2AR is highly reminiscent of GRK1 - mediated phosphorylation of rhodopsin .
 GRK2, GRK5 phosphoacceptor sites, beta2AR, GRK1, rhodopsin
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 GRK2, GRK5 phosphoacceptor sites, beta2AR, GRK1, rhodopsin