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 (PubMed:30514763, PubMed:30538131). O-fucosylates microneme protein MIC2 and may play a role in its stabilization (PubMed:30514763, PubMed:30538131). Probably by regulating protein O-fucosylation, may play a role in tachyzoite adhesion to and/or invasion of host cells; however, POFUT2 involvement in adhesion/invasion is controversial (PubMed:30514763, PubMed:30538131). GDP-beta-L-fucose + L-seryl-[protein] = 3-O-(alpha-L-fucosyl)-L-seryl-[protein] + GDP + H(+) GDP-beta-L-fucose + L-threonyl-[protein] = 3-O-(alpha-L-fucosyl)-L-threonyl-[protein] + GDP + H(+) Protein modification; protein glycosylation. Expressed in tachyzoites (at protein level). Loss of MIC2 O-fucosylation (PubMed:30514763, PubMed:30538131). Nuclear O-fucosylation is normal (PubMed:30538131). MIC2 protein levels are decreased by 50 percent. Abnormal MIC2 accumulation in the early/mid-secretory pathway (PubMed:30538131). The number of plaques caused by tachyzoite infection of human foreskin fibroblasts (HFF) is reduced by 40 percent (PubMed:30538131). The number of tachyzoites that are attached to or invaded the host HFFs is reduced. Egress from the HFFs is also partially impaired (PubMed:30538131). However, another study shows that loss of POFUT2 only leads to a small decrease in MIC2 protein levels and has no effect on MIC2 trafficking and interaction with M2AP (PubMed:30514763). Also, the number of plaques caused by tachyzoite infection of HFFs is reduced by only 20 percent and tachyzoite adhesion to and invasion of HFFs are normal (PubMed:30514763). Belongs to the glycosyltransferase 68 family.