The anchorosome, a special chromatin granule for the anchorage of the interphase chromosome to the nuclear envelope.
Peripheral chromatin granules bound to the nuclear envelope of rat liver nuclei have been further investigated. Judging by the results of Staphylococcal nuclease digestion of nuclei and electron microscopical observations, the peripheral granules have nucleosomal organization. As shown by ultraviolet radiation DNA-protein cross-linkage, the histone-like proteins present in the peripheral chromatin instead of histone H1 (Fais et al., 1982) are in close contact with DNA. The peripheral chromatin contains a DNA firmly bound to the lamina. This DNA, resistant to extraction in high salt, heparin and SDS, is protected against a DNase attack since, as shown by DNA electrophoresis data, high molecular weight molecules (up to 20 kbas) are still present in the lamina residue. However, the high molecular weight DNA disappeared if the nuclear envelope fraction was again DNase-digested after high salt treatment. Altogether, the data of the previous (Fais et al., 1982; Prusov et al., 1980: Prusov et al., 1982) and the present investigations demonstrate that the peripheral chromatin granules are endowed with properties which distinguish them from the bulk chromatin and account for the chromosome bond to the nuclear envelope during interphase. This is why we suggest the term "anchorosome" for the peripheral protein granule attached to the nuclear envelope.
Fais
D
D
Dipartimento A.Monroy di Biologia cellulare e dello Sviluppo dell'Universita di Palermo, Italia.
Prusov
A N
AN
Polyakov VYu
D000818:Animals; D002467:Cell Nucleus / Q000648:ultrastructure; D002843:Chromatin / Q000378:metabolism / Q000648:ultrastructure*; D002875:Chromosomes / Q000378:metabolism* / Q000648:ultrastructure; D004247:DNA / Q000378:metabolism; D007399:Interphase; D008854:Microscopy, Electron; D009685:Nuclear Envelope / Q000378:metabolism* / Q000648:ultrastructure; D009707:Nucleosomes / Q000648:ultrastructure*; D051381:Rats; D013347:Subcellular Fractions
D002843:Chromatin; D009707:Nucleosomes; D004247:DNA