Figure 9.

Myosin plays a novel role in vesicle tethering or fusion. This illustration portrays the known and hypothetical roles of myosin XI in delivery of CSCs to the plasma membrane. Based on evidence presented here, as well as recent publications, we predict that myosin not only transports CESA-containing vesicles in the cell cortex, but also participates in vesicle tethering or fusion after vesicles reach the CSC insertion sites that are defined by CELLULOSE SYNTHASE INTERACTIVE1 (CSI1) and microtubules. The potential role of myosin in exocytosis could be through interaction with the exocyst complex to stabilize or maintain an intact tethering complex required for fusion with the membrane.