(center map) (center map)PMID:15637053 in human fibrosarcoma HT1080 cells, phosphorylation of GPI by CK2 decreases its enzymatic activity and (non-phosphorylatable or phospho-mimetic mutants) in HT1080, knock-down of CK2 promotes GPI activity in vitro, in HT1080 cells, phosphomimetic GPI mutant forms tetramers in vitro, CK2 triggers GPI tetramerisation PMID:11004567 in vitro CK2 mediated phosphorylation of GPI on S185 in HT1080 cells, Ser phosphorylation of GPI