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INTRANUCLEAR NETWORK OF 3–5nm AND 8–10nm FIBERS IN EL‐4 LYMPHOMA CELLS
Author(s) -
PADROS MARIA R.,
GILES DEBRA M.,
SUAREZ MARIA D.
Publication year - 1997
Publication title -
cell biology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.932
H-Index - 77
eISSN - 1095-8355
pISSN - 1065-6995
DOI - 10.1006/cbir.1997.0149
Subject(s) - intermediate filament , nuclear matrix , rnase p , cytoskeleton , nucleus , biophysics , vimentin , actin , matrix (chemical analysis) , cell nucleus , protein filament , chemistry , cytoplasm , cell , biology , microbiology and biotechnology , chromatin , dna , biochemistry , rna , gene , immunohistochemistry , chromatography , immunology
While much evidence indicates a high degree of spatial organization in the nucleus, the underlying molecular structures that support it remain poorly characterized. By extracting with high concentrations of RNase A in a modification of the sequential extraction protocol of Penman, we have identified a novel intranuclear network in the mouse lymphoma cell line, EL‐4. Micrographs of embedment‐free sections of extracted cells reveal anastomosing filaments of two different diameters: 3–5nm and 8–10nm. The 3–5‐nm filaments are interconnected in many junctions and appear to blend smoothly into each other. The 8–10‐nm fibers frequently split into two 3–5‐nm filaments. Some 3–5‐nm fibers appear to be connected at 90° angles with the 8–10‐nm fibers. All junctions are smooth with no apparent junction protein. Flow cytometric analysis of RNase A‐ (and DNase I‐) extracted nuclear matrices indicates that they do not contain significant amounts of protein that react with anti‐actin and anti‐vimentin monoclonal antibodies. Extraction of EL‐4 nuclear matrices with high salt does not reveal 8–10‐nm core filaments described after similar treatment of tumor cell lines of cervical and mammary origin. The novel characteristics of the core filaments in EL‐4 lymphoma cells may reflect cell‐type specificity of the nuclear matrix.