24656
Using reporter gene and electrophoretic gel mobility shift assays we demonstrated that MK2 catalytic activity directly regulated the promoters of the fast fiber - specific myosin heavy chain IId / x and the slow fiber - specific sarco / endoplasmic reticulum Ca ( 2 + ) - ATPase ( SERCA ) 2 gene .
 Chemical: Ca ( 2 + )
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: Ca ( 2 + )