Concomitant translocation of Purα with its binding proteins (PurBPs) from nuclei to cytoplasm during neuronal development

Two Purα-binding proteins (PurBPs) were found in nuclear extract from mouse brain during P4-P10 by the overlay assay. At P14, they were decreased significantly in nuclear extract and increased in the S3 fraction, indicating their dynamic translocation during development. Western blot analysis also demonstrated concomitant translocation of Purα with the PurBPs during P7-P14, when neuronal circuit proceeds. Immunocytochemical study with cultured hippocampal neurons from rat E18 confirmed that nuclear Purα was translocated to cytoplasm after plating for 7-14 days. These results suggest that spatiotemporal translocation of Purα with the PurBPs from nuclei to cytoplasm has a crucial role in neuronal development.