Filamentous cross-bridges link intermediate filaments to the nuclear pore complexes.

Intermediate filament-nuclear matrix interactions were studied in cultured rat ventral prostate cells and isolated rat uterine epithelial cells. Cytokeratin filaments were identified by immunoelectron microscopy. In addition to conventional thin section of Triton X-100 treated cells, subcellular residues composed of intermediate filaments and nuclear matrix were critical-point dried and platinum-carbon replicated. The results demonstrate the presence of a previously unrecognized type of filamentous cross-bridges that link intermediate filaments to the nuclear pore complexes.