Sulfate transporter 3.4 (SULTR3;4) (SULTR3;4)

Sulfate transporter 3.4 (SULTR3;4), also known as SULTR-like Phosphorus Distribution Transporter (SPDT), is a transmembrane protein in plants that plays a critical role in the internal distribution of essential nutrients [3, 4]. Although it belongs to the sulfate transporter family, recent research has identified it as a specialized phosphate transporter that facilitates the transfer of inorganic phosphate from the xylem to the phloem [2, 5]. This xylem-to-phloem transfer is vital for the preferential allocation of phosphorus to developing tissues, such as seeds and grains, which is a key determinant of crop yield and nutritional quality [5, 13]. In addition to its role in phosphorus homeostasis, SULTR3;4 has been implicated in sulfate transport into chloroplasts, influencing abscisic acid (ABA) biosynthesis and the plant's response to abiotic stresses like salinity [1, 10]. In agricultural biotechnology, SULTR3;4 is a prominent target for gene editing to create low-phytate crops, which can improve mineral bioavailability and reduce environmental phosphorus pollution [5, 9]. While it is not a human therapeutic target, its human ortholog is SLC26A11, a member of the solute carrier family involved in anion exchange [8]. The protein's structure includes a transmembrane domain and a C-terminal STAS domain, which are essential for its transport activity and regulation [5, 14]. Understanding SULTR3;4's function provides insights into the evolution of substrate specificity within the SLC26/SulP transporter superfamily [2, 5].

Other names

SPDTSULTR-like phosphorus distribution transporterAt3g15990MSL1.3

H+/Pi symport; H+/Sulfate symport