Elucidating the molecular networks that regulate polarized cell growth, using functional genomics. (360G-Wellcome-093965_Z_10_Z)

Almost every living cell must maintain some degree of polarity, whether permanent or transient, in order to live and function correctly. There are many obvious examples of cell polarity provided by the mammalian system, including epithelial cells, neurons and photoreceptors. However, the fission yeast Schizosaccharomyces pombe provides one of the simplest and most easily studied examples. The rod shaped cells of this organism have two distinct regions, the hemispherical growing tips - where cells expand, with the addition of components to the cell wall and cell membrane - and the non-growing cell sides. Many factors are known to localise specifically to cell ends and organisation of the growth domains is highly dependent on microtubule-dependent intracellular transport mechanisms. However, our understanding of the complex regulatory networks involved in polarized growth regulation are extremely limited, with many regulators and regulatory principles likely remaining to be identified. New semi-automated methods allowing for high-throughput/high-content (HT/HC) data collection and analysis can be applied to rapidly and systematically look for novel genes involved in the regulation of polarized growth, which can then be used as a starting point to more fully elucidate their entire network. Data has already been collected from one such screen providing several interesting candidates. Additionally, in previous work, the motor protein Klp2 involved in microtubule organization during growth was investigated, with some interesting findings with regards to its in vivo activity. This may produce significant results solving a long-standing puzzle in S.pombe research and clarifying how microtubules are organised during interphase. Objectives 1. To continue investigating the regulation of the microtubule organiser Klp2, in particular its interaction with other regulatory proteins 2. To validate and further investigate candidate genes suggested by the previous screen 3. To identify further genes affecting cell polarity by carrying out a HT/HC screen for regulators of microtubule dynamics