CYTOLOGICAL ANALYSIS OF THE REACTION OF THE NUCLEOLAR RNA
AND RNA-BINDING PROTEINS TO OXIDATIVE STRESS IN HeLa CELLS
A.A. Mironova,1,2 N.V. Barykina,1,3 O.V. Zatsepina 1,*
1 M.M. Shemyakin—Yu. A. Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow,
2 Faculty of Bioengineering and Bioinformatics, M. V. Lomonosov Moscow State University,
and 3 P.K. Anokhin Research Institute of Normal Physiology RAMS, Moscow;
* e-mail: zatsepina_olga@mail.ru
The organization and functional activity of the nucleoli of mammalian cells can be modified in response to
various stress factors. However, data on the reaction of nucleoli to oxidative stress remain limited. In this paper,
we have studied the localization of nucleolar RNAs and two RNA-binding proteins — fibrillarin, a pre-rRNA
processing factor, and nucleophosmin/B23, a pre-ribosome assembly factor, in HeLa cells exposed to 1 mM
Í2Î2 up to four hours. We have shown that under the conditions used Í2Î2 does not induce death, but inhibits
rDNA transcription, reduces the total RNA content in the cells and the amount of 18S rRNA in the nucleoli, and
causes relocalization of fibrillarin and nucleophosmin/B23 to the nucleoplasm. To date, similar changes in the
localization of fibrillarin were described in mammalian cells only after HgCl2 treatment. Redistribution of nucleophosmin/
B23 observed in Í2Î2-treated cells occurred in mammalian cells under inhibition of rDNA transcription
and early rRNA processing. Overall, this study shows the high sensitivity of the nucleoli of HeLa cells
to acute oxidative stress, which is clearly evident on the cytological level.
Key words: fibrillarin, FISH, Í2Î2, nucleolus, nucleophosmin/B23, oxidative stress, pyronin Y, rRNA
| Back
| Contents
| Main |
|
