Phospho-mTOR (Ser2481) colocalizes with condensed chromosomes during metaphase

Abstract

Aim. To study the subcellular localization of phospho-mTOR (Ser2481) in cultured cells of human cancer cell lines. Methods. Immunofluorescent analysis of phospho-mTOR (Ser2481) subcellular localization in cultured MCF-7 (human breast adenocarcinoma) and HepG2 (human liver carcinoma) cells. Results. For the first time phospho-mTOR (Ser2481) was detected as bright spots situated in the equatorial region of chromosomes and co-localized with condensed chromosomes during metaphase. Conclusions. In this study, we describe for the first time the co-localization of phospho-mTOR (Ser2481) and chromosomes of the metaphase plate in the MCF-7 and HepG2 cells. Our data support the hypothesis that phospho-mTOR (Ser2481) could act as a CPP (chromosomal passenger protein)-like kinase, which takes part in the regulation of mitosis progression.