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6th ESACP Congress, Heidelberg, April 7-11, 1999 |
A039
Double-stranded ribonucleic acids (dsRNA)exhibit multiple biological
activities including the regulation of cell growth and differentiation.
In this investigation the formation of dsRNA was studied in differentiating
cells that after fixation were treated or non-treated with proteinase K.
Fluorescent in situ immuno- assay by using highly specific monoclonal
antibodies against the A-helix structure of natural dsRNA was performed.
These antibodies do not react with single-stranded (ss) dsRNA, ss- or dsRNA,
RNA-DNA hybrids, short helical regions which are present in tRNA, 5S RNA,
7S RNA, and viroids. As demonstrated on the retinoic acid-induced
differentiating mouse Neuro-2a cells treated with proteinase K, dsRNA
structures first appear in nucleus, then surround the nuclear envelope,
and finally enter the cytoplasm. The intra- cellular presence of dsRNAs
has a limited span of existence, because the completely differentiated
cells do not contain dsRNA nor in cytoplasm or nuclei, although secondary
appearence of dsRNA in nucleoli of senescent cells are evident. In cells
non-treated with proteinase K, dsRNAs are seen only in nuclei as a ring
located near the nuclear envelope. Our findings suggest that in
differentiating Neuro-2a cells, dsRNA displays complex spatial and
temporal organization being un-linked to proteins only when located nearly
to the nuclear envelope.
KINETICS OF CELL-DERIVED DOUBLE-STRANDED RIBONUCLEIC ACIDS DURING
DIFFERENTIATION
Bruvere R, Pilmane M, Feldmane G, Volrate A, Loza V
Biomedical Research and Study Centre, University of Latvia; Medical
Faculty, University of Latvi; Institute of Microbiology and Virology,
Riga, Latvia