Cell polarity in fission yeast: A matter of confining, positioning, and switching growth zones

The two key processes in growth polarisation are the generation of a confined region and the correct positioning of that region. Fission yeast has greatly contributed to the study of cell polarisation, particularly in the aspect of growth site positioning, which involves the interphase microtubule cytoskeleton. Here we review the mechanisms of growth polarity in vegetatively growing fission yeast cells. These seemingly simple cells show astonishingly complex growth polarity behaviour, including polarity switching and integrating multiple levels of control by the cell cycle machinery. We aim to extract and highlight the underlying concepts and discuss these in context of current understanding; showing how relevant proteins are networked to integrate the various machineries.

► Fission yeast cells grow cylindrical by positioning and confining growth at the poles.
► Redundant molecular systems may control growth site confinement.
► Microtubules deposit cell end marker proteins for growth site positioning.
► Cell end markers control a switch from monopolar to bipolar growth.
► Monopolar versus bipolar growth is coordinated with cell cycle progression.