Cytoplasmic and nuclear localization sites of phosphatidylinositol 3-kinase in human osteosarcoma sensitive and multidrug-resistant Saos-2 cells

Histochemistry and Cell Biology
N ZiniN M Maraldi

Abstract

The intracellular localization of phosphatidyl-inositol 3-kinase (PI 3-kinase) has been analyzed by western blotting, confocal, and electron microscopy immunocytochemistry in human osteosarcoma Saos-2 cells. By western blotting, the enzyme appears to be present in both the cytoplasmic and nuclear subfractions. By confocal microscope immunocytochemistry, the cytoplasmic fluorescence is localized in the perinuclear region and on a network of filaments, while a diffused signal is present in the nucleus, except for the nucleolar areas. Ultrastructural analyses on whole cells and on in situ matrix preparations reveal that nuclear PI 3-kinase is localized in interchromatin domains, in stable association with inner nuclear matrix components, while the enzyme diffused in the cytosol is partly associated with the cytoskeletal filaments. Quantitative evaluations indicate that, in a multidrug-resistant variant obtained by continuous exposure of Saos-2 cells to doxorubicin, the amount of nuclear and cytoplasmic PI 3-kinase is significantly lower than in the sensitive parental cell line. The nuclear localization of PI 3-kinase and its variation in multidrug-resistant cells, characterized by a reduced mitotic index, are consistent with the d...Continue Reading

References

Aug 1, 1992·Seminars in Cell Biology·R F Irvine, N Divecha
Oct 1, 1992·Proceedings of the National Academy of Sciences of the United States of America·S Raffioni, R A Bradshaw
Sep 1, 1992·The Journal of Histochemistry and Cytochemistry : Official Journal of the Histochemistry Society·N M MaraldiF A Manzoli
Jan 25, 1991·Cell·L C CantleyS Soltoff
Sep 21, 1989·Nature·M J Berridge, R F Irvine
Oct 16, 1989·Biochemical and Biophysical Research Communications·D N TatakisR Dziak
Jan 1, 1987·Breast Cancer Research and Treatment·A FojoI Pastan
Aug 1, 1994·BioEssays : News and Reviews in Molecular, Cellular and Developmental Biology·R Kapeller, L C Cantley
Jan 1, 1993·Annual Review of Biochemistry·M M Gottesman, I Pastan
Jan 1, 1993·Advances in Experimental Medicine and Biology·C S Morrow, K Cowan
Aug 13, 1993·Cell·N DivechaR F Irvine
Mar 15, 1993·The Biochemical Journal·H BanfićR F Irvine
Dec 1, 1992·Trends in Cell Biology·G Panayotou, M D Waterfield

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Citations

Jan 20, 2004·Pharmacology & Therapeutics·Alberto M MartelliLucio Cocco
Jun 1, 2001·Advances in Enzyme Regulation·L CoccoF A Manzoli
Jan 1, 1997·Advances in Enzyme Regulation·N M MaraldiF A Manzoli
Jun 1, 2000·Advances in Enzyme Regulation·N M MaraldiF A Manzoli
Oct 19, 2002·Biochimica Et Biophysica Acta·Luca M NeriAlberto M Martelli
Mar 13, 2009·Cardiovascular Research·Shigeki MiyamotoMark A Sussman
Apr 21, 2006·Biochimica Et Biophysica Acta·Lucio CoccoFrancesco A Manzoli
Aug 10, 2005·Journal of Cellular Biochemistry·Fenghua LiuAlonzo H Ross
Apr 17, 2001·The Journal of Biological Chemistry·D BacquevilleM Breton-Douillon
Sep 25, 1999·Journal of Cellular Physiology·N M MaraldiF A Manzoli
Jul 3, 2019·Cells·Enrique CastanoPavel Hozák
Jan 8, 1999·Biochemical and Biophysical Research Communications·M MarchisioL M Neri
May 9, 2001·Biochimica Et Biophysica Acta·L CoccoF A Manzoli

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