Fig. 1. Immunolocalization of polyadenylation/translation factors in dendrites of cultured hippocampal neurons. (A) Fourteen day rat primary hippocampal cultures were immunostained with antibodies directed against poly(A) polymerase (PAP), the 100 kDa subunit of CPSF (CPSF100), Aurora, maskin and eIF-4E, and co-stained with monoclonal antibody for synaptophysin (sy38) which locates synapses. (B) A higher magnification of dendrites taken from selected areas (white rectangles) in (A) demonstrates that these factors occasionally are co-localized with synapses (arrows). (C) The specificity of the anti-PAP, CPSF, Aurora, eIF-4E and maskin antibodies was evaluated by immunoblotting using the mouse brain extract. Each of these antibody preparations recognized one major band of the expected molecular weight (arrows), PAP, 70 kDa; CPSF, 100 kDa; Aurora, 47 kDa; eIF4E, 25 kDa; maskin, 150 kDa. Scale bars, 10 µm.