Ml. Niswonger et Tj. Ohalloran, A NOVEL ROLE FOR CLATHRIN IN CYTOKINESIS, Proceedings of the National Academy of Sciences of the United Statesof America, 94(16), 1997, pp. 8575-8578
Using clathrin-minus Dictyostelium cells, we identified a novel requir
ement for clathrin during cytokinesis. In suspension culture, clathrin
-minus cells failed to divide and became large and multinucleate. This
cytokinesis deficiency was not attributable to a pleiotropic effect o
n the actomyosin cytoskeleton, since other cellular events driven by m
yosin II (e.g., cortical contraction and capping of concanavalin A rec
eptors) remained intact in clathrin-minus cells, Examination of cells
expressing myosin II tagged with green fluorescent protein showed that
clathrin-minus cells failed to assemble myosin II into a functional c
ontractile ring. This inability to localize myosin II to a particular
location was specific for cytokinesis, since clathrin-minus cells movi
ng across a substrate localized myosin II properly to their posterior
cortexes, These results demonstrate that clathrin is essential for con
struction of a functional contractile ring during cell division.