FIGURE 3. PAR exchange between the spindle and cytoplasm is slow.
From the following article:
Poly(ADP-ribose) is required for spindle assembly and structure
Paul Chang, Myron K. Jacobson and Timothy J. Mitchison
Nature 432, 645-649(2 December 2004)
doi:10.1038/nature03061
a, Real-time localization of PAR in the spindle. X-rhodamine-labelled anti-PAR Fab fragments were added to cycled spindles containing Alexa-488-labelled tubulin and visualized. PAR localization to the spindle largely overlaps with tubulin. b, Rate of PAR exchange between the spindle and cytoplasm. Xenopus egg extract spindles incubated with X-rhodamine-labelled anti-PAR Fab or anti-TPX2 antibodies were partially purified by sedimentation, diluted 1:20 into unlabelled mitotic egg extract and images taken every 30 s for 20 min using wide-field microscopy. The graph depicts the percentage relative fluorescence intensity with respect to time 0 at every minute for three separate experiments. PAR (red line) exhibits a slow rate of cytoplasmic exchange relative to TPX2 (blue line), longer than known spindle components. Error bars represent standard deviation of three independent experiments. Below are images of anti-PAR and anti-TPX2 antibodies at 0, 10 and 20 min.
