Abstract
Abstract: :
Purpose: To further characterize the intracellular localization of RPGR. Methods: Native RPGR was localised by immunofluorescence in three human cell lines (HeLa, U2OS, ARPE19) and in human retina using four different antibodies raised against synthetic peptides or expressed recombinant peptide. Cells were also labelled with markers for centrosomes, Golgi and spliceosomes. Results: With all four antibodies, punctate nuclear labelling was found in each cultured cell type and in all retinal layers, including the RPE. Discrete localisation was also observed outside of the nucleus in interphase cells, similar to that seen with pericentrin, using antibodies against the C-terminal of ORF15. This labelling co-localised with gamma-tubulin, a marker for the centrosome. Weaker spindle pole labelling was observed in mitotic cells. Co-localisation was not observed with markers for either the Golgi or spliceosome. Pre-immune sera gave no labelling. Conclusions: Native RPGR has a dual intracellular localisation in cultured cells. It is present in the nucleus and also in the cytoplasm where it co-localises with gamma-tubulin in metaphase and mitotic cells. This localisation indicates that RPGR is associated with the centrosome. RPGR may participate, directly or indirectly, in the synthesis or function of microtubules.
Keywords: proteins encoded by disease genes • immunohistochemistry • retinal degenerations: cell biology