Negatively regulates the high-osmolarity glycerol (HOG) pathway through its negative regulation of the HOG1 kinase activity. Mediates the binding between the PTC1 phosphatase and the PBS2 MAP/ERK kinase (MEK). With PTC1, regulates endoplasmic reticulum inheritance through the cell wall integrity (CWI) MAPK pathway by modulating the MAPK, SLT2