Phosphatase catalytic subunit of the trehalose synthase complex that catalyzes the production of trehalose from glucose-6-phosphate and UDP-alpha-D-glucose in a two step process (PubMed:11004189). The disaccharide trehalose serves as a storage carbohydrate that is mobilized during nutrient stress and spore germination (Probable). Together with ntp1, regulates the level of trehalose as a protectant for cell integrity during thermal, osmotic, and oxidative stress (Probable). alpha,alpha-trehalose 6-phosphate + H2O = alpha,alpha-trehalose + phosphate Carbohydrate biosynthesis. Component of the trehalose synthase complex that contains at least tps1, ntp1, and tpp1 (Probable). Interacts with tps1 (PubMed:12153582). Interacts with ntp1 (PubMed:12153582). Induced by thermal stress, and osmotic stress (at protein level) (PubMed:11004189). Induced by oxidative stress (PubMed:11004189). Increases cellular trehalose-6-phosphate level during thermal stress. In the N-terminal section; belongs to the glycosyltransferase 20 family. In the C-terminal section; belongs to the trehalose phosphatase family.