Physical model of contractile ring initiation in dividing cells

¹ Weizmann Institute of Science

^* To whom correspondence should be addressed. E-mail: nirgov{at}wisemail.weizmann.ac.il.

Submitted on April 23, 2007
Revised on June 18, 2007
Accepted on 17 September 2007

	Abstract

We present a physical mechanism to describe initiation of the contractile ring during cell division. The model couples the membrane curvature with the contractile forces produced by protein clusters attached to the membrane. These protein clusters are mobile on the membrane and possess either an isotropic or an anisotropic spontaneous curvature. Our results show that under these conditions the contraction force gives rise to an instability that corresponds in a closed cellular system to the initiation of the contractile ring. We find a "quantization" of this process at distinct length-scales, which we compare to available data for different types of eukaryote cells.

Key Words: Contractile ring, Cytokinesis, Dynamic instability, Spontaneous curvature