Na(+)/sulfate cotransporter with a probable high-affinity for sulfate and a proteasome dependent turnover. Up-regulated by sulfur deprivation. No effect on sulfate uptake, due to the redundancy with SLT1 and SULTR2. Slt1 and slt2, as well as slt1 and sultr2 double mutants show a 50% decline in uptake while the slt1, slt2 and sultr2 triple mutant exhibits no increase in sulfate uptake capacity when deprived of sulfur. Modified regulation of the SLT3 gene that becomes up-regulated by sulfur deprivation instead of down-regulated as in wild-type. Belongs to the divalent anion:Na+ symporter (DASS) superfamily. Na+/sulfate symporter (TC 2.A.47.4) family.