The nuclear matrix: three-dimensional architecture and protein composition.
The structural filament network of the nucleus is prepared while still connected to the cytoskeleton. The relatively gentle procedure removes about 98% of the DNA and at least 86% of the histones. The matrix is bounded by an outer nuclear lamina connected to the cytoskeletal framework, as well as the inner filaments. The filaments range in diameter from 3 to 22 nm, and are organized in a three-dimensional anastomosing network in which nucleoli are enmeshed. The nuclear matrix is separated from the cytoskeletal framework by a double detergent and then partitioned into a chromatin fraction and a matrix fraction by nuclease and high salt. Two-dimensional gel electrophoresis shows that the proteins of the cytoskeleton, chromatin and nuclear matrix are very different. A major protein found in all fractions cofocuses with actin. Vimentin is largely associated with the nuclear matrix, probably as a corona external of filaments.
D000818:Animals; D002467:Cell Nucleus / Q000032:analysis / Q000648:ultrastructure*; D002843:Chromatin / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D004247:DNA / Q000032:analysis; D006657:Histones / Q000032:analysis; D006801:Humans; D007526:Isoelectric Point; D051379:Mice; D008854:Microscopy, Electron; D008970:Molecular Weight; D011506:Proteins / Q000032:analysis
D002843:Chromatin; D006657:Histones; D011506:Proteins; D004247:DNA