(A) PSPC1 is detected in E14.5 midbrain neurons, and has an interaction with PSF in these cells. (B) An interaction with PSF is shown in HIS IP, PSPC1 IP and LMX1B IP, in MN9D cells overexpressing LMX1B-HIS. (C ) Again, PSF interacts with LMX1B, as shown in a HIS and LMX1B IP. LMX1B IP reveals clear pull-down of LMX1B-HIS, which also observed in the PSF IP, and in lower amount in the control IP. (D) PSF interacts with LMX1B in developing midbrain neurons. (E) Confirmation of the interaction of PSF with LMX1B(-HIS), and with NURR1. NURR1 IP reveals pull down of the protein, however this is not shown in HIS or LMX1B IP. Moreover, in a NURR1 IP, no LMX1B could be observed. Ctrl, control IP with normal host serum; IP, immunoprecipitation; (-), MN9D cells transfected with control(empty) vector; (LMX1B-HIS) MN9D cells transfected with LMX1B-HIS overexpression vector.