PIKfyve
The principal enzymatic activity of PIKfyve is to phosphorylate PtdIns3P to PtdIns(3,5)P2. PIKfyve activity is responsible for the production of both PtdIns(3,5)P2 and phosphatidylinositol 5-phosphate (PtdIns5P). PIKfyve is a large protein, containing a number of functional domains and expressed in several spliced forms.