Complementation assays. Acceptor lysate derived from the LCLs of a patient carrying hyperphosphorylated paratarg-7 (lanes 1a-1c) or from LCLs of a healthy carrier of wild-type paratarg-7 (lanes 2a-2c) were incubated with lysate buffer as control (lane a) or with donor lysates derived from the LCLs of a healthy carrier of wild-type paratarg-7 (lane b), or with lysates derived from the LCLs of a patient carrying hyperphosphorylated paratarg-7 (lane c). After incubation (37°C, 48 hours), the samples were subjected to IEF followed by immunodetection of FLAG-tagged paratarg-7 using FLAG Abs. In lane 1b, dephosphorylation of hyperphosphorylated paratarg-7 was observed, while in lane 1c no dephosphorylation was detected, indicating a compromised dephosphorylation in carriers of hyperphosphorylated paratarg-7. In the reverse approach using wild-type FLAG-tagged paratarg-7 as acceptor and LCL extracts (lanes 2a-2c) as donors, the upper band representing hyperphosphorylated paratarg-7 was only detected when extracts derived from LCLs of the patient carrying hyperphosphorylated paratarg-7 were used as donors (lane 2c).