Fig. 6.
A model of osmotic sensing through Yvc1p. (A)A flow chart listing the key events from the rise of external osmolarity to the release of Ca2+ into the cytoplasm. (B) An illustration of how an outwardly directed pressure (e.g., by mechanical force; large arrow, Upper) or an inwardly directed pressure (e.g., by external hyperosmolarity; large arrow, Lower) can both generate tension on the membrane (small arrows), which activates the MS Yvc1p. The transient osmotic pressure in A postulated may occur very locally and does not necessarily correlate with gross changes in vacuole shape as drawn (B Lower).