title: Analysis, regulation, and roles of endosomal phosphoinositides.
abstract: Phosphoinositides (PIs) are minor lipid components of cellular membranes that play critical roles in membrane dynamics, trafficking, and cellular signaling. Among the seven naturally occurring PIs, the monophosphate phosphatidylinositol 3-phosphate (PtdIns3P) and the bisphosphate phosphatidylinositol 3,5-bisphosphate [PtdIns(3,5)P2] have been mainly associated with endosomes and endosomal functions. Metabolic labeling and HPLC analysis revealed that a bulk of PtdIns3P is constitutively present in cells, making it the only detectable product of the enzymes phosphoinositide 3-kinases in unstimulated, normal cells. The use of specific tagged-PtdIns3P-binding domains later demonstrated that this constitutive PtdIns3P accumulates in endosomes where it critically regulates trafficking and membrane dynamics.
authors.affiliation: Inositide Signalling Group, Centre for Diabetes, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom.
authors.forename: Tania
authors.initials: T
authors.lastname: Maffucci
authors.affiliation: Inositide Signalling Group, Centre for Diabetes, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom. Electronic address: m.falasca@qmul.ac.uk.
authors.forename: Marco
authors.initials: M
authors.lastname: Falasca
mesh_terms: D000818:Animals; D001665:Binding Sites; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D011992:Endosomes / Q000378:metabolism*; D006801:Humans; D008856:Microscopy, Fluorescence; D018129:Phosphatidylinositol Phosphates / Q000302:isolation & purification / Q000502:physiology*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D013194:Staining and Labeling; D033921:Vesicular Transport Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: D018129:Phosphatidylinositol Phosphates; D033921:Vesicular Transport Proteins
keywords: HPLC; Microscopy analysis; Phosphatidylinositol 3,5-bisphosphate; Phosphatidylinositol 3-phosphate; Phosphoinositides; Phosphoinositides-binding domains