Catalyzes the reaction that attaches fucose through an O-glycosidic linkage to a conserved serine or threonine residue in the consensus sequence C1-X-X-S/T-C2 of thrombospondin type I repeats (TSRs) where C1 and C2 are the first and second cysteines of the repeat, respectively . O-fucosylates members of several protein families including the ADAMTS, the thrombospondin (TSP) and spondin families (Probable) . Required for the proper secretion of ADAMTS family members such as ADAMTSL1 and ADAMTS13 (, ). The O-fucosylation of TSRs is also required for restricting epithelial to mesenchymal transition (EMT), maintaining the correct patterning of mesoderm and localization of the definite endoderm (By similarity).
Subcellular locations: Endoplasmic reticulum, Golgi apparatus
Mainly located in the endoplasmic reticulum.
Isoform A is expressed in fetal liver and peripheral blood lymphocytes. Isoform B is expressed in spleen, lung, testis, bone marrow, thymus, pancreas, prostate, fetal brain, fetal liver and fetal kidney. Isoform C is expressed in brain, heart, spleen, liver, lung, stomach, testis, placenta, skin, thymus, pancreas, mammary gland, prostate, fetal brain, fetal liver and fetal heart.