Fig. 1.

SAF-A localizes across chromatin and impacts Cot-1 RNA localization when mutated but not when depleted. For all images: color channels are separated in black and white. Scale bars 5 μm. Cell types: normal human fibroblasts (Tig-1) & mouse/human hybrid cells with human chromosome 4 (Hybrid). A Diagram of endogenous SAF-A protein and the human C280-GFP SAF-A deletion mutant. B SAF-A is detected over chromatin, but not within non-chromatin SC35 domains, as seen by structured illumination microscopy (SIM) image. C Close-up of indicated region of nucleus in image B (SIM). D–E Human C₀T-1 RNA remains localized over the human chromosome in hybrid control cells (D) and in cells where DNA and histone chromatin proteins are removed (canonical nuclear matrix prep) (E). F Expression of the C280-GFP SAF-A mutant results in release of human C₀T-1 RNA from the human chromosome in hybrid cells (SIM). G C₀T-1 RNA remains localized to the human chromosome in hybrid cells when endogenous mouse SAF-A is present (short arrow) and when it is eliminated using siRNA (long arrows)