May be involved in the polarity establishment process. Suppresses the lethality of KEX2-GAS1 double null mutant when overexpressed. Interacts with ZDS1 and ZDS2. Localizes primarily to the growing sites, such as an incipient bud site in the cells with emerging buds, a bud tip in small- or medium-budded cells, or a cell periphery in large-budded cells. Phosphorylated by CDC28. Present with 1550 molecules/cell in log phase SD medium. Belongs to the SKG6/TOS2 family.