Adenosine-3-Phospho-5-Phosphosulfate Transporter 1 (PAPST1)

Sulfotransferases use an activated form of PAPS, as a common sulfate donor for sulfation of glycoproteins, proteoglycans, and glycolipids in the endoplasmic reticulum and Golgi apparatus. SLC35B2 is located in the microsomal membrane and transports PAPS from the cytosol, where it is synthesized, into the Golgi lumen. PAPST1 is a type III transmembrane protein with 8 transmembrane domains. Real-time PCR detected highest PAPST1 expression in placenta, followed by pancreas, mammary gland, and skeletal muscle. Moderate expression was detected in all other tissues examined except colon, heart, and prostate, where expression was weak. Immunofluorescence microscopy and cell fractionation localized epitope-tagged PAPST1 to the Golgi membrane in transfected human cell lines.