sentence: In vitro analyses using REMSA have found that SBP2 exhibits selective high affinity binding activity to Gpx4 and Trxr1 SECIS ( 36 ) while in vivo binding of selenoprotein mRNAs by SBP2 via immunoprecipitation of the proteins and quantitation of bound mRNAs have shown that SBP2 exhibits strong preferential binding to SelW , Sel15 , Gpx4 , SelH , Trxr1 , Dio2 and SelK mRNAs over others ( 22 ) .