Journal of Cell Science 115, e2305-e2305 (2002)
Copyright © 2002 The Company of Biologists Limited
Centrosome flares
Centrosomes, the major microtubule-organizing centres in animal cells, each
comprise two centrioles and a surrounding cloud of pericentriolar material
(PCM). The PCM contains a filamentous `centromatrix' plus additional proteins
such as centrosomin (CNN) and is often thought to be a static structure.
Thomas Kaufman and co-workers show that it can in fact be highly dynamic (see
p. 4707). Imaging CNN-GFP
fusion proteins in live Drosophila embryos, they demonstrate that
particles containing CNN and another centrosomal protein, D-TACC, oscillate
radially back and forth from the centrosome. These `centrosome flares' are
cell cycle regulated: flare activity decreases during metaphase, increasing
again at telophase. The authors show that interfering with microtubule
dynamics inhibits flaring, concluding that the process is driven by
association of CNN with dynamic astral microtubules. Interestingly, during
mitosis, the flares extend only as far as the actin cages surrounding the
spindle; moreover, disruption of the actin cytoskeleton increases the distance
flares travel, allowing them to jump to neighbouring centrosomes. The flares
thus appear to be limited by the actin cage and might play a part in
organizing its boundary.
Related articles in JCS:
- The centrosome is a dynamic structure that ejects PCM flares
- Timothy L. Megraw, Sandhya Kilaru, F. Rudolf Turner, and Thomas C. Kaufman
JCS 2002 115: 4707-4718.
[Abstract]
[Full Text]
