FIGURE 6: Hypothetical model for how changes in the cell wall are sensed by mechanosensors and transmitted to RAS and lead to filamentous growth. Starvation induces changes in the cell wall organisation, and this leads to changes in wall elasticity that are sensed by the mechanosensors. The mechanosensors act as inhibitors of Ras1/2 and/or adenylate cyclase (AC) under normal growth conditions. Starvation relieves this inhibition resulting in increased levels of cAMP and increased PKA activity, which triggers filamentous growth.