Component of a complex required to localize phosphatidylinositol 4-kinase (PI4K) to the plasma membrane (PubMed:26571211). The complex acts as a regulator of phosphatidylinositol 4-phosphate (PtdIns(4)P) synthesis (PubMed:26571211). HYCC1 plays a key role in oligodendrocytes formation, a cell type with expanded plasma membrane that requires generation of PtdIns(4)P (PubMed:26571211). Its role in oligodendrocytes formation probably explains its importance in myelination of the central and peripheral nervous system (PubMed:16951682, PubMed:26571211). May also have a role in the beta- catenin/Lef signaling pathway (Probable). {ECO:0000269|PubMed:16951682, ECO:0000269|PubMed:26571211, ECO:0000305|PubMed:10910037}. This is the function of HYCC1 (hyccin PI4KA lipid kinase complex subunit 1, Ensembl gene identifier ENSG00000122591).