Using Fluorescence Resonance Energy Transfer (fret) Technology Cam And The Plk1 The Time And Space Interaction

The cell-division cycle has to be regulated temporally and spatially. The spatial distributions of cell-cycle regulators and their dynamic behaviors show that their localization are important in the response to specific cell-cycle or checkpoint signals, and have raised the possibility that regulators may be activated or inactivated in discrete compartments of the cell, or on specific sub cellular structures to coordinate changes in the sub cellular architecture.Calcium is a universal signaling molecule and involved in regulating mitotic transitions. In mammalian cells, calmodulin (CaM) is a highly conserved Ca2+ binding protein that contains four EF-hand Ca2+ binding motifs. Intracellular CaM levels are regulated as progressing through the cell cycle. Although Ca2+/CaM is required for proliferation in both unicellular and multicellular eukaryotes, the essential targets of Ca2+/CaM-dependent pathways required for cell proliferation remain elusive.Our results suggest that CaM can directly interact with Plk1 at specific time and sub cellular architecture of cell cycle. Fluorescent resonance energy transfer (FRET) analyses show that in interphase CaM can't directly bind to Plk1, while in mitosis entry, CaM co-localizes with polo-like kinase 1 (Plk1) at centrosome, they may directly interact with each other when cell enter into anaphase, the direct interaction between CaM and Plk1 can be detected by FRET imaging,. With the cell going through anaphase to telophase, the CaM mainly distributs in the midzone while Plkl mainly distributs in the midbody, the direct interaction between CaM and Plk1 gradually disappears.