CDK5R1 mRNA is bound by nELAV proteins in SH-SY5Y cells. A) Endogenous mRNP complexes were selectively immunoprecipitated from SH-SY5Y cells using the pan neuronal ELAV and the irrelevant IgG antibodies. The bound mRNAs were analyzed by RT-PCR with primer pairs specific for CDK5R1 (left panel) and GAP-43 (right panel). MW, Molecular weight marker; +, positive control (total SH-SY5Y cDNA); -, negative control (no sample). B) In vitro RNA-protein binding experiments were performed by UV cross-linking of different P32-radiolabelled regions from CDK5R1 3'UTR and brain protein lysate. A selective immunoprecipitation of the formed mRNP complex was performed using the nELAV antibody (lanes 2–5). As a negative control a mix of all the different riboprobes was used and immunoprecipitated by the IgG antibody (-, lane 1), while GAP-43 3'UTR riboprobe was used as a positive control (+, lane 5).