PI3K (IPR001263) is an enzyme that phosphorylates phosphoinositide at the 3-hydroxyl of the inositol ring. Substrate presentation is mediated by phosphoinositide 3-kinase (PI3-kinase). Phosphoinositide 4-kinase (PI4K, cd00871) phosphorylates the hydroxyl group at position 4 on the phosphoinositide ring as part of the initial phase of the phosphatidylinositol cycle. All PI3Ks and PI4Ks possess a conserved PI kinase domain, and the majority also contain diverse extra domains that are involved in protein-protein or phospholipid-protein interactions. The phosphoinositide kinase (PIK, PS51545) domain is the structural backbone of all PI3 and a conserved area in PI4 kinase that may play a role in substrate presentation. PI3K regulates clathrin-independent dynein-dependent endocytosis in a particular manner (40) . Dynamin, a major GTPase, is involved in the formation of many vesicles (41) .