Has a partially redundant function to ECM33 in cell wall integrity. May be involved in a repair mechanism activated in response to cell wall damage. Identified as GPI-anchored plasma membrane protein (GPI-PMP) as well as non-covalently-linked, soluble protein of the cell wall. Secreted by regenerating protoplasts. In budded cells, concentrates at the surface of the buds. Positively regulated by cell integrity signaling through MPK1 in response to cell wall perturbation. Induction is dependent on transcription factor RLM1. Extensively N- and O-mannosylated. Mannoprotein called haze protective factor from wine that is able to prevent visible wine protein haze formation. This mannoprotein showed haze-protective activity against wine proteins and BSA when either was heated in white wine. Present with 11700 molecules/cell in log phase SD medium. Belongs to the SPS2 family.