How Cells Put on Caps by Themselves

Science's STKE  25 Feb 2003:
Vol. 2003, Issue 171, pp. tw87-TW87
DOI: 10.1126/stke.2003.171.tw87

Cells are generally polarized. How can a single cell, in the absence of external cues, generate a polarized distribution of its constituent parts? Wedlich-Soldner et al. address this question in the yeast Saccharomyces cerevisiae. Overexpression of the protein Cdc42--a protein known to be involved in polarization of mammalian cells--enabled a cell to polarize spontaneously. It seems that random accumulations of the protein get locked into a process of continued accumulation that arises from a positive feedback in protein localization involving actin-based targeted secretion. This process leads to the formation of a cap of the protein at the cell surface that can then go on to promote the polarization of the cell.

R. Wedlich-Soldner, S. Altschuler, L. Wu, R. Li, Spontaneous cell polarization through actomyosin-based delivery of the Cdc42 GTPase. Science 299, 1231-1235 (2003). [Abstract] [Full Text]