In order to continue to meet the demands of proliferation under environmental stress, cells have to coordinate their growth and division with available resources. The target of rapamycin (TOR) acts as a major nutrient sensor and is involved in regulating the coupling of cell growth and cell cycle progression in response to alterations in the nutrient environment.  Comparative biology has been particularly revealing in understanding signalling networks. The fission yeast S. pombe and budding yeast S. cerevisiae diverged approximately 350 million years ago. S. pombe is a particularly excellent model for the study of cell growth and cell division as, unlike S. cerevisiae, S. pombe has retained through evolution complex heterochomatin, the RNAi machinery, large centromeres, gene splicing, telomere function and conserved checkpoints among others features. Furthermore, while the TOR kinases were first discovered in S. cerevisiae, its upstream regulators TSC1/TSC2 that are regulated by AMPK signalling in most eukaryotic cells are conserved in S. pombe but not found in S. cerevisiae. Together, this makes S. pombe an ideal model system with which to establish core conserved principles of environmental control of TOR signalling and cell proliferation. We have exploited S.pombe to uncover a novel TOR inhibitor (Scyl1) required for survival upon stress to endo-membranes along with identifying a role for TOR signalling in cytokinesis.