Plasma membrane osmosensor that activates the high osmolarity glycerol (HOG) MAPK signaling pathway in response to high osmolarity. Mediates resistance to oxidative stress. Controls the activation of the CEK1 MAP kinase. Influences the molecular weight and polymer distribution of cell wall mannan. Involved in invasive filamentation into semi-solid medium and plays a role in morphological dimorphic transition which is a differentiation program characteristic of C.albicans and which is known to play a major role in pathogenesis. Forms homooligomers. Repressed by caspofungin. Belongs to the SHO1 family.