Biopolymers and cell. 2008; 24 (1): 35 - 40

Subcellular localization of S6K1 and S6K2 forms of ribosomal protein S6 kinase in primary monolayer culture of rat thyrocytes

A. I. Khoruzhenko, O. V. Cherednyk, V. V. Filonenko

The main aim of this work was to determine subcellular localization of S6K1 and S6K2 forms of ribosomal protein S6 kinase in the primary monolayer culture of thyrocytes obtained from undamaged follicles. In the thyroid follicles S6K1, S6K2 have been detected predominantly in the cytoplasm of the cells, however, in the monolayer culture of thyrocytes in the course of follicles outspreading S6K1 and S6K2 have been observed in nuclei as well. Such redistribution of S6K was not directly related to the appearance of proliferating Ki-67 positive cells. At the same time there was a correlation between the appearance of S6K1, S6K2 positive nuclei in monolayer thyrocyte culture and decrease in thyroglobulin content in cultured cells. Thus, the obtained results indicated that the down regulation of thyrocyte functional activity caused by the loss of follicle organization was accompanied by subcellular redistribution of S6K1 and S6K2

Key words: ribosomal protein S6 kinase, thyrocytes, primary culture.