Classically, chromosomal functions in DNA repair and sister chromatid association have been assigned to the cohesin proteins. More recent studies have provided evidence that cohesins also localize to the centrosomes, which organize the bipolar spindle during mitosis. Depletion of cohesin proteins is associated with multi-polar mitosis in which spindle pole integrity is compromised. However, the spindle pole defects after cohesin depletion could be an indirect consequence of a chromosomal cohesion defect which might impact centrosome integrity via alterations to the spindle microtubule network. Here we show that the cohesin Rad21 is required for centrosome integrity independently of its role as a chromosomal cohesin. Thus, Rad21 may promote accurate chromosome transmission not only by virtue of its function as a chromosomal cohesin, but also because it is required for centrosome function.
Bibliographical noteFunding Information:
We thank R. Kuriyama for ongoing discussions throughout the project and for critical reading of the manuscript. We thank K. Luby-Phelps and L. Lanier for help with the time lapse microscopy, K. Sullivan, S. Doxsey, S. Jensen and H. Yu for reagents. L.A.D.M. was partially funded by CONACyT, J.F.G.A. by BFU2008-03579/BMC and P.E. by BFU2008-02947-C02-02/ BMC, and D.J.C. by a seed grant from the University of Minnesota Academic Health Center.