Live-cell imaging reveals sustained centromere binding of CENP-T via CENP-A and CENP-B

At the centromere, a network of proteins, the kinetochore, assembles in order to grant correct chromatin segregation, In this study the dynamics and molecular interactions of the inner kinetochore protein CENP-T were analyzed employing a variety of fluorescence microscopy techniques in living human cells. Acceptor.-bleaching FRET indicates that CENP-T directly associates with CENP-A and CENP-B. CENP-T exchange into centromeres is restricted to the S-phase: of the cell cycle as revealed by FRAP suggesting a coreplicational loading mechanism, as we have recently also demonstrated for CENP-I. These properties make CENP-T one of the basic inner kinetochore proteins with most further proteins binding downstream, suggesting a fundamental hole of CENP-T in kinetochore function. (C) 2008 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim