Myc-XErp1 CaMKII- ZBR- (T195A C583A) IVT was in vitro phosphorylated by recombinant PKA and isolated by α-Myc immunoprecipitation. The immunoprecipitate was supplemented with calcium and treated with recombinant hs_CaN and calmodulin as indicated. Samples were taken at the indicated time points and immunoblotted for the catalytic calcineurin subunit CnA and pSer335 XErp1. The pSer335 XErp1 membrane was stripped and reprobed for the Myc-tag. Asterisk indicates the IgG heavy chain. 