Publication of the week
week 25 - A research group led by Kevin Sullivan reveals dynamic assembly of a histone fold protein complex during the cell cycle.
The scientists studied the CENP-W/T complex that integrates with the chromatin of centromeres and thereby plays a role in cell division. Although histone fold complexes can interact stably with DNA, the CENP-T/W complex turned out not to be stably associated.
The scientists imaged cell lines that expressed CLIP-tagged CENP-W or CENP-T. They noticed that the proteins assembled at the centromers after DNA replication, even though they are always expressed. Furthermore a conditional labeling strategy showed that the CENPs-T and –W that assemble prior to mitosis are newly assembled. According to the scientists this may point at a cycling function for CENP-T/W “that triggers kinetochore assembly as cells enter mitosis in each new cell cycle”*.
Top: Immunofluorescence of a human mitotic spindle at metaphase. DAPI stained chromosomes are blue, microtubules in green and centromeres in red. A 3-dimensional rendition of this image can be seen at http://www.chromosome.ie/ccb/sullivan/spindles/ Middle: HeLa cells labeled with CLIP-tagged CENP-T (red) with tubulin staining (green) to identify stages in mitosis.
Bottom: Deltavision Core equipped with Quantifiable Laser Module (QLM) for photodynamics expriments, housed in an environmental chamber and maintained at 37C.
Prendergast, L., C. van Vuuren, A. Kaczmarczyk, V. Doering, D. Hellwig, N. Quinn, C. Hoischen, S. Diekmann and K. F. Sullivan "Premitotic Assembly of Human CENPs -T and -W Switches Centromeric Chromatin to a Mitotic State." PLoS Biol 9(6): e1001082.
Last Modified: 27-06-2011
